githelp: cleanup one more abort message

This makes the string localizable, uses the more standard hint argument, quotes
the problem option so it stands out, and kills a stray apostrophe.

hgext/githelp.py

@@ -94,10 +94,9 b' def parseoptions(ui, cmdoptions, args):'
             try:
                 args.remove(flag)
             except Exception:
-                raise error.Abort(
-                    "unknown option {0} packed with other options\n"
-                    "Please try passing the option as it's own flag: -{0}" \
-                    .format(ex.opt))
+                msg = _("unknown option '{0}' packed with other options")
+                hint = _("please try passing the option as its own flag: -{0}")
+                raise error.Abort(msg.format(ex.opt), hint=hint.format(ex.opt))
 
             ui.warn(_("ignoring unknown option %s\n") % flag)
 

tests/test-githelp.t

@@ -43,8 +43,8 b' githelp on a command with standalone unr'
 
 githelp on a command with unrecognized option packed with other options should fail with error
   $ hg githelp -- commit -pv
-  abort: unknown option v packed with other options
-  Please try passing the option as it's own flag: -v
+  abort: unknown option 'v' packed with other options
+  (please try passing the option as its own flag: -v)
   [255]
 
 githelp for git rebase --skip