evolve: remove a check which is already done by rewriteutil.precheck()
We have tests to check if fold is being performed on public cset.
There is no changes in test files because testing that never touched
the part this patch removes, and already caught in rewriteutil.precheck()
# Copyright 2019 Pierre-Yves David <pierre-yves.david@octobus.net>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
def hastopicext(repo):
"""True if the repo use the topic extension"""
return getattr(repo, 'hastopicext', False)