tests/test-gendoc-it.t

remotefilelog: use the correct redirection in tests

The test were using '2>%1' which just redirect stderr in the "%1" file. The
intend was '2>&1' which redirect stderr on stdin.

This impact tests because some commit were picking up this '%1' files.

Differential Revision: https://phab.mercurial-scm.org/D7588

#require docutils gettext

  $ $TESTDIR/check-gendoc it
  checking for parse errors