bundle2: keep hint close to the primary message when remote abort

The remote hint message was ignored when reporting the remote error and
passed to the local generic abort error. I think I might initially have
tried to avoid reimplementing logic controlling the hint display depending of
the verbosity level. However, first, there does not seems to have such verbosity
related logic and second the resulting was wrong as the primary error and the
hint were split apart. We now properly print the hint as remote output.

mercurial/exchange.py

@@ -904,7 +904,9 b' def _pushbundle2(pushop):'
             raise error.Abort(_('missing support for %s') % exc)
         except bundle2.AbortFromPart as exc:
             pushop.ui.status(_('remote: %s\n') % exc)
-            raise error.Abort(_('push failed on remote'), hint=exc.hint)
+            if exc.hint is not None:
+                pushop.ui.status(_('remote: %s\n') % ('(%s)' % exc.hint))
+            raise error.Abort(_('push failed on remote'))
     except error.PushkeyFailed as exc:
         partid = int(exc.partid)
         if partid not in pushop.pkfailcb:

tests/test-bundle2-exchange.t

@@ -518,16 +518,16 b' Doing the actual push: Abort error'
   pushing to ssh://user@dummy/other
   searching for changes
   remote: Abandon ship!
+  remote: (don't panic)
   abort: push failed on remote
-  (don't panic)
   [255]
 
   $ hg -R main push http://localhost:$HGPORT2/ -r e7ec4e813ba6
   pushing to http://localhost:$HGPORT2/
   searching for changes
   remote: Abandon ship!
+  remote: (don't panic)
   abort: push failed on remote
-  (don't panic)
   [255]