Forgot to reshow mouse cursor when exiting grab/hide mode

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%402072

src/video/gem/SDL_gemmouse.c

@@ -172,6 +172,7 @@ GEM_CheckMouseMode(_THIS)
         GEM_mouse_relative = SDL_TRUE;
     } else {
         GEM_mouse_relative = SDL_FALSE;
+        graf_mouse(M_ON, NULL);
     }
 }