keepalive: use collections.defaultdict for host map
Cleaning up the code as part of debugging Python 3 issues.
Differential Revision: https://phab.mercurial-scm.org/D5718
fixbundle() {
grep -v 'saving bundle' | grep -v 'saved backup' | \
grep -v added | grep -v adding | \
grep -v "unable to find 'e' for patching" | \
grep -v "e: No such file or directory" | \
cat
}