Correct checks for gradient stop position.

It may be <= 1 in the final version and not < 1.

See #11897.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@63866 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/graphcmn.cpp

@@ -520,7 +520,7 @@ void wxGraphicsGradientStops::Add(const wxGraphicsGradientStop& stop)
     }
     else
     {
-        wxFAIL_MSG( "invalid gradient stop position >= 1" );
+        wxFAIL_MSG( "invalid gradient stop position > 1" );
     }
 }