[osg] Update dependency sdl2 as sdl1

[NancyLi1013]

Since this file #include <SDL/SDL.h> is from sdl1 instead of sdl2.
I also tried to use SDL2 to build, but there were many errors in SDL2/SDL.h.
So I update the dependency sdl2 as sdl1 in CONTROL file.

Related issue #10320

Note: The feature tested pass in x86-windows triplet.

[dan-shaw]

/azp run

[NancyLi1013]

osg-qt failed on Linux platform due to this regression:

CMake Error at /ci/myagent/_work/1/s/installed/x64-linux/share/cmake/Qt5Gui/Qt5GuiConfig.cmake:15 (message):
  The imported target "Qt5::Gui" references the file

     "/ci/myagent/_work/3/s/installed/x64-linux/lib/libEGL.so"

  but this file does not exist.  Possible reasons include:

  * The file was deleted, renamed, or moved to another location.

  * An install or uninstall procedure did not complete successfully.

  * The installation package was faulty and contained

     "/ci/myagent/_work/1/s/installed/x64-linux/share/cmake/Qt5Gui/Qt5GuiConfigExtras.cmake"

  but not all the files it references.

[dan-shaw]

Is this similar to the fix in #10082 ?

[NancyLi1013]

@dan-shaw
Thanks for your reminder.
It seems that the PR #10082 has included this issue.
I close this PR now.