MinGW tweak: Follow up on last patch: Define this baseClass static as well.

git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@3331 3789f03b-4d11-0410-bbf8-ca57d06f2519
diff --git a/win/rfb_win32/MsgWindow.cxx b/win/rfb_win32/MsgWindow.cxx
index 95bd523..306b1c3 100644
--- a/win/rfb_win32/MsgWindow.cxx
+++ b/win/rfb_win32/MsgWindow.cxx
@@ -88,7 +88,7 @@
   }
 }
 
-MsgWindowClass baseClass;
+static MsgWindowClass baseClass;
 
 //
 // -=- MsgWindow