vcl: gtk 2.4 is checked at configure time

Change-Id: I08993551473fb9a8284e2a1ed772c99050f785d8
Reviewed-on: https://gerrit.libreoffice.org/12251Reviewed-by: Michael Stahl <mstahl@redhat.com>
Tested-by: Michael Stahl <mstahl@redhat.com>

vcl/unx/gtk/app/gtkinst.cxx

@@ -97,9 +97,6 @@ extern "C"
         if ( !g_thread_supported() )
             g_thread_init( NULL );
 
-#if !GTK_CHECK_VERSION(2,4,0)
-#error "Requires gtk 2.4.0+ for lock hooking"
-#endif
         gdk_threads_set_lock_functions (GdkThreadsEnter, GdkThreadsLeave);
         SAL_INFO("vcl.gtk", "Hooked gdk threads locks");