commit: no longer allow empty commit with the 'force' argument (API)

The new way to allow empty commit is to temporarily set the
'ui.allowemptycommit' config option.


  allowemptyback = repo.ui.backupconfig('ui', 'allowemptycommit')
  try:
      repo.ui.setconfig('ui', 'allowemptycommit', True)
      repo.commit(...)
  finally:
      repo.ui.restoreconfig(allowemptyback)

All known uses of force for allowing empty commits have been removed, so let's
remove it from the allowemptycommits condition.

mercurial/localrepo.py

@@ -1462,7 +1462,7 b' class localrepository(object):'
             cctx = context.workingcommitctx(self, status,
                                             text, user, date, extra)
 
-            allowemptycommit = (wctx.branch() != wctx.p1().branch() or force
+            allowemptycommit = (wctx.branch() != wctx.p1().branch()
                                 or extra.get('close') or merge or cctx.files()
                                 or self.ui.configbool('ui', 'allowemptycommit'))
             if not allowemptycommit: