histedit: improve missing rule suggestion

include actual suggested text

hgext/histedit.py

@@ -1214,7 +1214,7 b' def verifyactions(actions, state, ctxs):'
     if missing:
         raise error.Abort(_('missing rules for changeset %s') %
                 missing[0][:12],
-                hint=_('do you want to use the drop action?'))
+                hint=_('use "drop %s" to discard the change') % missing[0][:12])
 
 def newnodestoabort(state):
     """process the list of replacements to return

tests/test-histedit-arguments.t

@@ -164,7 +164,7 b' Test that missing revisions are detected'
   > pick 08d98a8350f3 4 five
   > EOF
   abort: missing rules for changeset c8e68270e35a
-  (do you want to use the drop action?)
+  (use "drop c8e68270e35a" to discard the change)
   [255]
 
 Test that extra revisions are detected