chg: ignore already closed fds when cleaning up
This should fix this error we see in the CI from time to time:
```
--- /tmp/mercurial-ci/tests/test-chg.t
+++ /tmp/mercurial-ci/tests/test-chg.t.err
@@ -187,6 +187,26 @@
$ chg bulkwrite --pager=on --color no --config ui.formatted=True
paged! 'going to write massive data\n'
killed! (?)
+ Traceback (most recent call last):
+ File "/tmp/hgtests._uvojvqb/install/lib/python/mercurial/commandserver.py", line 509, in _serverequest
+ sv.cleanup()
+ File "/tmp/hgtests._uvojvqb/install/lib/python/mercurial/chgserver.py", line 382, in cleanup
+ self._restoreio()
+ File "/tmp/hgtests._uvojvqb/install/lib/python/mercurial/chgserver.py", line 461, in _restoreio
+ os.close(fd)
+ OSError: [Errno 9] Bad file descriptor
+ Traceback (most recent call last):
+ File "/tmp/hgtests._uvojvqb/install/lib/python/mercurial/commandserver.py", line 693, in _acceptnewconnection
+ self._runworker(conn)
+ File "/tmp/hgtests._uvojvqb/install/lib/python/mercurial/commandserver.py", line 744, in _runworker
+ prereposetups=[self._reposetup],
+ File "/tmp/hgtests._uvojvqb/install/lib/python/mercurial/commandserver.py", line 509, in _serverequest
+ sv.cleanup()
+ File "/tmp/hgtests._uvojvqb/install/lib/python/mercurial/chgserver.py", line 382, in cleanup
+ self._restoreio()
+ File "/tmp/hgtests._uvojvqb/install/lib/python/mercurial/chgserver.py", line 461, in _restoreio
+ os.close(fd)
+ OSError: [Errno 9] Bad file descriptor
[255]
```
edition = "2018"
max_width = 79
wrap_comments = true
error_on_line_overflow = true