[PATCH evolve-ext] Fixed case where AttributeError can be thrown when importing wireproto

[andrew at apastron.co]

# HG changeset patch
# User Andrew Fischer <andrew at apastron.co>
# Date 1533040717 18000
#      Tue Jul 31 07:38:37 2018 -0500
# Node ID c4a2d0e5bf18c229fc559323295900e421e246ef
# Parent  2af10d0a59e06c7f84d33eb1eb5eec4a880df162
Fixed case where AttributeError can be thrown when importing wireproto

diff -r 2af10d0a59e0 -r c4a2d0e5bf18 hgext3rd/topic/discovery.py
--- a/hgext3rd/topic/discovery.py	Tue Jul 31 11:25:57 2018 +0200
+++ b/hgext3rd/topic/discovery.py	Tue Jul 31 07:38:37 2018 -0500
@@ -16,7 +16,7 @@
 try:
     from mercurial import wireproto
     wireproto.branchmap
-except ImportError: # <= hg-4.5
+except (AttributeError, ImportError): # <= hg-4.5
     from mercurial import wireprotov1server as wireproto
 
 def _headssummary(orig, pushop, *args, **kwargs):