vo_opengl: fall back to gcc thread local storage (2)

Commit 1a6f3c56 added a fallback for the case when C11 TLS was not
available, but GCC TLS was. But it forget to enable VAAPI EGL interop in
the build system in this case.

Just remove the build system check. Should someone find a compiler that
works on Linux and does not support GCC extensions or C11, it will still
compile and just fail to init at runtime.

Actually fixes #2631 (hopefully).

wscript

@@ -712,7 +712,6 @@ video_output_features = [
     }, {
         'name': 'vaapi-egl',
         'desc': 'VAAPI EGL',
-        'deps': [ 'c11-tls' ], # indirectly
         'deps_any': [ 'vaapi-x-egl', 'vaapi-wayland' ],
         'func': check_true,
     }, {