remotefilelog-test: glob some flaky output line
This is similar to ee0959e7d435. The affected line is flaky underload, yet the
final result is correct. The command involves background pre-check of output,
these are not stable probably because they run in parallel in multiple process.
If it become useful to start testing precise internal details of the, they will
have to be tested in a more appropriate framework than `.t` tests.
Differential Revision: https://phab.mercurial-scm.org/D8179