egl: Fix detection in configure script on systems without X11 (bug #5270) In recent versions of EGL headers on Linux, the MESA_EGL_NO_X11_HEADERS macro is deprecated and has been replaced with EGL_NO_X11. As a result, the configure script would fail the compilation check for EGL headers and disable EGL (and by extension, Wayland) support when X11 headers are not installed. Fix this by adding the correct macro to disable X11 support in the headers.