histedit: temporarily shorten name of 'constraints' variable

An upcoming changeset will make the line where this variable is used
slightly too long. Other later changesets will clean that up further and makes
the variable unnecessary, so this is only temporary and it does seems useful to
put anything more complicate in place.

hgext/histedit.py

@@ -1379,25 +1379,25 b' def verifyactions(actions, state, ctxs):'
     for action in actions:
         action.verify(prev)
         prev = action
-        constraints = action.constraints
-        for constraint in constraints:
+        constrs = action.constraints
+        for constraint in constrs:
             if constraint not in _constraints.known():
                 raise error.ParseError(_('unknown constraint "%s"') %
                         constraint)
 
         if action.node is not None:
             ha = node.hex(action.node)
-            if _constraints.noother in constraints and ha not in expected:
+            if _constraints.noother in constrs and ha not in expected:
                 raise error.ParseError(
                     _('%s "%s" changeset was not a candidate')
                      % (action.verb, ha[:12]),
                     hint=_('only use listed changesets'))
-            if _constraints.forceother in constraints and ha in expected:
+            if _constraints.forceother in constrs and ha in expected:
                 raise error.ParseError(
                     _('%s "%s" changeset was not an edited list candidate')
                      % (action.verb, ha[:12]),
                     hint=_('only use listed changesets'))
-            if _constraints.noduplicates in constraints and ha in seen:
+            if _constraints.noduplicates in constrs and ha in seen:
                 raise error.ParseError(_(
                         'duplicated command for changeset %s') %
                         ha[:12])