Removed one more OS X warning about deprecates function.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@7239 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

src/Fl_Gl_Choice.cxx

@@ -380,7 +380,11 @@ void fl_no_gl_context() {
 #  elif defined(__APPLE_QUARTZ__)
   // warning: the Quartz version should probably use Core GL (CGL) instead of AGL
   AGLContext ctx = aglGetCurrentContext();
+#   if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5
+  if (ctx) aglSetWindowRef(ctx, NULL);
+#    else
   if (ctx) aglSetDrawable(ctx, NULL);
+#    endif
   aglSetCurrentContext(0);
 #  else
 #    error unsupported platform