Log Message:
py-mercurial: update to 6.4.4.

= Mercurial 6.4.4 =

 * clonebundles: filter out invalid schemes instead of failing on them
 * doc: format argument for date uses strftime format string (issue6818)
 * test: make test-contrib-perf.t more robust
 * revlog: fix a bug in revlog splitting
 * bundles: clarify streaming v2 bundle usage
 * delta-find: fix pulled-delta-reuse-policy=forced behavior
 * dirstate: fall back to v1 if reading v2 failed
 * revlog: avoid possible collision between directory and temporary index