glx: Dead code removal

Remove a redundant ifndef GLX_USE_APPLEGL

Signed-off-by: Jeremy Huddleston <jeremyhu@apple.com>

src/glx/glxcurrent.c

@@ -160,12 +160,10 @@ _X_HIDDEN void
 __glXSetCurrentContextNull(void)
 {
    __glXSetCurrentContext(&dummyContext);
-#ifndef GLX_USE_APPLEGL
 #if defined(GLX_DIRECT_RENDERING) && !defined(GLX_USE_APPLEGL)
    _glapi_set_dispatch(NULL);   /* no-op functions */
    _glapi_set_context(NULL);
 #endif
-#endif
 }
 
 _X_EXPORT GLXContext