[mscgen mode] correct a typo in the mscgen non-rregression

Author: sverweij

mode/mscgen/mscgen_test.js

@@ -25,7 +25,8 @@
   );
 
   MT("xù/ msgenny keywords classify as 'base'",
-    "[base watermark wordwrapentities]",
+    "[base watermark]",
+    "[base wordwrapentities]",
     "[base alt loop opt ref else break par seq assert]"
   );