[Cleanup] Handle system dependent defines through autoheader & common-config.h


git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@2890 3789f03b-4d11-0410-bbf8-ca57d06f2519
diff --git a/common/rfb/util.cxx b/common/rfb/util.cxx
index 5745432..7950a1d 100644
--- a/common/rfb/util.cxx
+++ b/common/rfb/util.cxx
@@ -30,6 +30,10 @@
  * is provided ``as is'' without express or implied warranty.
  */
 
+#ifndef HAVE_COMMON_CONFIG_H
+#include <common-config.h>
+#endif
+
 #include <rfb/util.h>
 
 // Provide strcasecmp() and/or strncasecmp() if absent on this system.