Don't do Unicode check under Windows.

Shelarcy says that Windows does not have wxconfig.

darcs-hash:20080320085542-db91e-f9e5bd2270cef10cbd5e8ff669de77ffbd23f8dc.gz

configure

@@ -757,17 +757,20 @@ fi
 #--------------------------------------------------------------------
 
 # confirm that we have unicode enabled
-`$wxconfig --unicode=yes`
-if test "$?" = 0; then
-  echo " wxWidgets Unicode support found"
-else
-  echo ""
-  echo " I can't find the Unicode version of wxWidgets!"
-  echo ""
-  echo " Did you configure configure wxWidgets with --enable-unicode?"
-  echo " If you have more than one copy, are you passing in the right"
-  echo " version via --wx-config?"
-  exit 1
+
+if test "$wxtoolkit" != "msw"; then
+  `$wxconfig --unicode=yes`
+  if test "$?" = 0; then
+    echo " wxWidgets Unicode support found"
+  else
+    echo ""
+    echo " I can't find the Unicode version of wxWidgets!"
+    echo ""
+    echo " Did you configure configure wxWidgets with --enable-unicode?"
+    echo " If you have more than one copy, are you passing in the right"
+    echo " version via --wx-config?"
+    exit 1
+  fi
 fi
 
 #--------------------------------------------------------------------