xwayland: make context current to check GL version
glGetString(GL_VERSION)
will return NULL without a current context.
Commit dabc7d8b (“xwayland: Fall back to GLES2 if we don't get at least
GL 2.1 in glamor”) would check the context is created, but it is made
current just after, so the call to epoxy_gl_version()
would return 0,
hence defeating the version check.
Make the context current prior to call epoxy_gl_version()
.
Fixes: dabc7d8b Closes: #932 (closed) Signed-off-by: Olivier Fourdan ofourdan@redhat.com