phase: say "Returns 0" instead of "Return 0" like other command help stable

phase: say "Returns 0" instead of "Return 0" like other command help

--- a/mercurial/commands.py	Mon Mar 03 23:37:59 2014 +0530
+++ b/mercurial/commands.py	Mon Mar 03 15:50:45 2014 +0900
@@ -4483,7 +4483,7 @@
 
         public < draft < secret
 
-    Return 0 on success, 1 if no phases were changed or some could not
+    Returns 0 on success, 1 if no phases were changed or some could not
     be changed.
     """
     # search for a unique phase argument