[PATCH 2 of 2] py3: build help of compression engines in bytes

[Yuya Nishihara]

# HG changeset patch
# User Yuya Nishihara <yuya at tcha.org>
# Date 1539433045 -7200
#      Sat Oct 13 14:17:25 2018 +0200
# Node ID 921feabe152110773b8b85818b149a99166b9f74
# Parent  b8a16cf84c34d254df7ff276e49e6d5fd327eb8b
py3: build help of compression engines in bytes

Removes "b''" from help.

diff --git a/mercurial/util.py b/mercurial/util.py
--- a/mercurial/util.py
+++ b/mercurial/util.py
@@ -3867,11 +3867,10 @@ def bundlecompressiontopics():
         if not bt or not bt[0]:
             continue
 
-        doc = pycompat.sysstr('``%s``\n    %s') % (
-            bt[0], engine.bundletype.__doc__)
+        doc = b'``%s``\n    %s' % (bt[0], pycompat.getdoc(engine.bundletype))
 
         value = docobject()
-        value.__doc__ = doc
+        value.__doc__ = pycompat.sysstr(doc)
         value._origdoc = engine.bundletype.__doc__
         value._origfunc = engine.bundletype