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
cat >> $HGRCPATH <<EOF
[extensions]
narrow=
[ui]
ssh=python "$RUNTESTDIR/dummyssh"
[experimental]
changegroup3 = True
EOF