discovery: revise hint message introduced by changeset b00ba31313c3

This patch revises hint message from "for detail about" introduced by
changeset b00ba31313c3 to "for details about", to unify it with the
hint message introduced by proceeding patch.

mercurial/discovery.py

@@ -316,7 +316,7 b' def checkheads(repo, remote, outgoing, r'
                     error = (_("push creates multiple headed new branch '%s'")
                              % (branch))
                     hint = _("merge or"
-                             " see \"hg help push\" for detail about"
+                             " see \"hg help push\" for details about"
                              " pushing new heads")
         elif len(newhs) > len(oldhs):
             # strip updates to existing remote heads from the new heads list

tests/test-push-warn.t

@@ -368,7 +368,7 b' Pushing muliple headed new branch:'
   pushing to ../f
   searching for changes
   abort: push creates multiple headed new branch 'f'
-  (merge or see "hg help push" for detail about pushing new heads)
+  (merge or see "hg help push" for details about pushing new heads)
   [255]
   $ hg push --branch f --new-branch --force ../f
   pushing to ../f