gpg: pass 'editform' argument to 'cmdutil.getcommiteditor'

This patch passes 'editform' argument according to the format below:

  EXTENSION[.COMMAND][.ROUTE]

  - EXTENSION: name of extension
  - COMMAND: name of command, if there are two or more commands in EXTENSION
  - ROUTE: name of route, if there are two or more routes in COMMAND

In this patch, 'sign' is used as COMMAND, and ROUTE is omitted.

hgext/gpg.py

@@ -277,8 +277,9 def sign(ui, repo, *revs, **opts):
                              % hgnode.short(n)
                              for n in nodes])
     try:
+        editor = cmdutil.getcommiteditor(editform='gpg.sign', **opts)
         repo.commit(message, opts['user'], opts['date'], match=msigs,
-                    editor=cmdutil.getcommiteditor(**opts))
+                    editor=editor)
     except ValueError, inst:
         raise util.Abort(str(inst))