httppeer: avoid large dumps when we don't see an hgweb repo

When we don't get an hgweb protocol response, we dump the response to
the user for diagnostic purposes (it might be a cgitb message, for
instance).

But if we try to clone a bundle, we don't want to show the
entire bundle in the error message. Also, we don't want fetch the
full bundle multiple times during fallback. So we only fetch 1k here.

mercurial/httppeer.py

@@ -152,7 +152,7 b' class httppeer(wireproto.wirepeer):'
             raise error.RepoError(
                 _("'%s' does not appear to be an hg repository:\n"
                   "---%%<--- (%s)\n%s\n---%%<---\n")
-                % (safeurl, proto or 'no content-type', resp.read()))
+                % (safeurl, proto or 'no content-type', resp.read(1024)))
 
         if proto.startswith('application/mercurial-'):
             try: