Added one liner mentioning that mozilla.org provides only one vote

per bug.

webtools/bugzilla/votehelp.html

@@ -40,6 +40,10 @@ can either vote a little for many bugs, or vote a lot for a few bugs.
 
 <p>
 
+At Mozilla.org, each user receives only one vote per bug.
+
+<p>
+
 To look at votes:
 
 <ul>