Ignore KeyError on double close for logging handler.

_clear_all_handlers will sometimes double close a handler, in this case
a KeyError will be raised. http://bugs.python.org/issue8581

Will upstream.

BUG=none
TEST=Running in production.

Change-Id: I85bf973d194e9113ec00602fbcd269383767a269
Reviewed-on: http://gerrit.chromium.org/gerrit/3705
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Tested-by: Dale Curtis <dalecurtis@chromium.org>
1 file changed