update sdl to v0.3.4 (Patch allow gcc10 )

[ttys3]

build under gcc10 will result on error:

 note: /usr/bin/ld: /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_gesture.c.o):(.bss.WAYLAND_wl_proxy_get_user_data+0x0): multiple definition of `WAYLAND_wl_proxy_get_user_data'; /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_events.c.o):(.bss.WAYLAND_wl_proxy_get_user_data+0x0): first defined here
          /usr/bin/ld: /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_gesture.c.o):(.bss.WAYLAND_wl_proxy_set_user_data+0x0): multiple definition of `WAYLAND_wl_proxy_set_user_data'; /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_events.c.o):(.bss.WAYLAND_wl_proxy_set_user_data+0x0): first defined here
          /usr/bin/ld: /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_gesture.c.o):(.bss.WAYLAND_wl_proxy_add_listener+0x0): multiple definition of `WAYLAND_wl_proxy_add_listener'; /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_events.c.o):(.bss.WAYLAND_wl_proxy_add_listener+0x0): first defined here
          /usr/bin/ld: /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_gesture.c.o):(.bss.WAYLAND_wl_proxy_destroy+0x0): multiple definition of `WAYLAND_wl_proxy_destroy'; /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_events.c.o):(.bss.WAYLAND_wl_proxy_destroy+0x0): first defined here
          /usr/bin/ld: /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_gesture.c.o):(.bss.WAYLAND_wl_proxy_marshal_constructor_versioned+0x0): multiple definition of `WAYLAND_wl_proxy_marshal_constructor_versioned'; /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_events.c.o):(.bss.WAYLAND_wl_proxy_marshal_constructor_versioned+0x0): first defined here
          /usr/bin/ld: /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_gesture.c.o):(.bss.WAYLAND_wl_proxy_marshal_constructor+0x0): multiple definition of `WAYLAND_wl_proxy_marshal_constructor'; /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_events.c.o):(.bss.WAYLAND_wl_proxy_marshal_constructor+0x0): first defined here
          /usr/bin/ld: /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_gesture.c.o):(.bss.WAYLAND_wl_proxy_create+0x0): multiple definition of `WAYLAND_wl_proxy_create'; /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_events.c.o):(.bss.WAYLAND_wl_proxy_create+0x0): first defined here
          /usr/bin/ld: /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_gesture.c.o):(.bss.WAYLAND_wl_proxy_marshal+0x0): multiple definition of `WAYLAND_wl_proxy_marshal'; /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_events.c.o):(.bss.WAYLAND_wl_proxy_marshal+0x0): first defined here
          /usr/bin/ld: /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_keyboard.c.o):(.bss.WAYLAND_wl_proxy_get_user_data+0x0): multiple definition of `WAYLAND_wl_proxy_get_user_data'; /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_events.c.o):(.bss.WAYLAND_wl_proxy_get_user_data+0x0): first defined here
          /usr/bin/ld: /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_keyboard.c.o):(.bss.WAYLAND_wl_proxy_set_user_data+0x0): multiple definition of `WAYLAND_wl_proxy_set_user_data'; /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_events.c.o):(.bss.WAYLAND_wl_proxy_set_user_data+0x0): first defined here
          /usr/bin/ld: /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_keyboard.c.o):(.bss.WAYLAND_wl_proxy_add_listener+0x0): multiple definition of `WAYLAND_wl_proxy_add_listener'; /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_events.c.o):(.bss.WAYLAND_wl_proxy_add_listener+0x0): first defined here
          /usr/bin/ld: /tmp/rustcSwsrGo/libsdl2_sys-ab14be8f9d7d1911.rlib(SDL_keyboard.c.o):(.bss.WAYLAND_wl_proxy_destroy

this PR resolved the problem: Rust-SDL2/rust-sdl2#1010

related issue: neovide/neovide#306

[aclysma]

I generally avoid bumping the minimum version of dependencies as this makes this library unusable with older versions. I'd like to avoid forcing downstream projects to upgrade to a new version of libraries like skia or sdl2 to pick up fixes in skulpin. More rationale here: #42

You should be able to use any version of sdl2 >=0.33 without this change. You can update (and downgrade) to the version of your choice with cargo update -p sdl2 --precise 0.34.3

[ttys3]

@aclysma thanks for the precise param. seems good.