Fix 100% CPU utilization in C component while health check still reports as fine

[sergystepanov]

worker03-1     | corrupted double-linked list
worker03-1     | SIGABRT: abort
worker03-1     | PC=0x7f0275a4a52b m=6 sigcode=18446744073709551610
worker03-1     | signal arrived during cgo execution
worker03-1     |
worker03-1     | goroutine 20 gp=0xc0001fba40 m=6 mp=0xc0001e1008 [syscall]:
worker03-1     | runtime.cgocall(0xa5ffc0, 0xc00049f8c8)
worker03-1     |        /usr/local/go/src/runtime/cgocall.go:157 +0x4b fp=0xc00049f8a0 sp=0xc00049f868 pc=0x409e6b
worker03-1     | github.com/giongto35/cloud-game/v3/pkg/encoder/h264._Cfunc_h264_destroy(0x7f021d69ba40)
worker03-1     |        _cgo_gotypes.go:409 +0x3f fp=0xc00049f8c8 sp=0xc00049f8a0 pc=0xa0129f
worker03-1     | github.com/giongto35/cloud-game/v3/pkg/encoder/h264.(*H264).Shutdown.func1(0x0?)
worker03-1     |        /tmp/cloud-game/pkg/encoder/h264/x264.go:180 +0x34 fp=0xc00049f900 sp=0xc00049f8c8 pc=0xa021f4
worker03-1     | github.com/giongto35/cloud-game/v3/pkg/encoder/h264.(*H264).Shutdown(0x9fc22a?)

 corrupted double-linked list
Aug 08 23:11:36 cloud-gaming-usw 051034d19030[2458672]: SIGABRT: abort
Aug 08 23:11:36 cloud-gaming-usw 051034d19030[2458672]: PC=0x7f0997beb52b m=8 sigcode=18446744073709551610
Aug 08 23:11:36 cloud-gaming-usw 051034d19030[2458672]: signal arrived during cgo execution
Aug 08 23:11:36 cloud-gaming-usw 051034d19030[2458672]:
Aug 08 23:11:36 cloud-gaming-usw 051034d19030[2458672]: goroutine 20 gp=0xc0001fd6c0 m=8 mp=0xc000262008 [syscall]:
Aug 08 23:11:36 cloud-gaming-usw 051034d19030[2458672]: runtime.cgocall(0xa5f430, 0xc0003c7498)
Aug 08 23:11:36 cloud-gaming-usw 051034d19030[2458672]:         /usr/local/go/src/runtime/cgocall.go:157 +0x4b fp=0xc0003c7470 sp=0xc0003c7438 pc=0x409e6b
Aug 08 23:11:36 cloud-gaming-usw 051034d19030[2458672]: github.com/giongto35/cloud-game/v3/pkg/worker/caged/libretro/nanoarch._Cfunc_bridge_retro_load_game(0x7f09291225f0, 0xc0003587e0)
Aug 08 23:11:36 cloud-gaming-usw 051034d19030[2458672]:         _cgo_gotypes.go:488 +0x48 fp=0xc0003c7498 sp=0xc0003c7470 pc=0x9eb388
Aug 08 23:11:36 cloud-gaming-usw 051034d19030[2458672]: github.com/giongto35/cloud-game/v3/pkg/worker/caged/libretro/nanoarch.(*Nanoarch).LoadGame.func4(0xc0003587e0)

• Use mutex when switching media encoders #468