test: simplify `debugformat` matching in test-copies-chain-merge
This will make the test less sensible to unrelated format changing.
Differential Revision: https://phab.mercurial-scm.org/D11893
from __future__ import absolute_import, print_functionimport sysfor line in sys.stdin: if line.lower() in ("message-id: \n", "in-reply-to: \n"): line = line[:-2] print(line, end="")