wireproto: remove unnecessary exception trapping

The `try..except error.Abort` was added in 8474be4412ca back in
2012. The intent was to ensure a failing pushkey hook didn't crash
the server.

Since that changeset, repo.pushkey() and the hooks mechanism is
now much more robust about trapping errors itself. As such, we no
longer need this try..except block. So it has been removed.

Differential Revision: https://phab.mercurial-scm.org/D1996

mercurial/wireproto.py

@@ -914,11 +914,8 b' def pushkey(repo, proto, namespace, key,'
 
         proto.redirect()
 
-        try:
-            r = repo.pushkey(encoding.tolocal(namespace), encoding.tolocal(key),
-                             encoding.tolocal(old), new) or False
-        except error.Abort:
-            r = False
+        r = repo.pushkey(encoding.tolocal(namespace), encoding.tolocal(key),
+                         encoding.tolocal(old), new) or False
 
         output = proto.restore()