tests: fix differing output between py2 and py3

db9e33beb0fb broke the tests because of the difference in bytestring repr
between py2 and py3. Rather than backout that change for so little, I figured
I'd fix it myself.
Hopefully Python 2 supports gets dropped very soon.

Differential Revision: https://phab.mercurial-scm.org/D9987

mercurial/changegroup.py

@@ -685,7 +685,7 b' def _resolvenarrowrevisioninfo('
                 # We failed to resolve a parent for this node, so
                 # we crash the changegroup construction.
                 raise error.Abort(
-                    b'unable to resolve parent while packing %r %r'
+                    b"unable to resolve parent while packing '%s' %r"
                     b' for changeset %r' % (store.indexfile, rev, clrev)
                 )
 

tests/test-narrow-pull.t

@@ -147,7 +147,7 b' Can pull into repo with a single commit'
   $ hg clone -q --narrow ssh://user@dummy/master narrow2 --include "f1" -r 0
   $ cd narrow2
   $ hg pull -q -r 1
-  remote: abort: unexpected error: unable to resolve parent while packing b'00manifest.i' 1 for changeset 0
+  remote: abort: unexpected error: unable to resolve parent while packing '00manifest.i' 1 for changeset 0
   transaction abort!
   rollback completed
   abort: pull failed on remote