Martin von Zweigbergk <martinvonz@google.com> [Wed, 17 Apr 2019 14:42:23 -0700] rev 42255
copies: move check for experimental.copytrace==<falsy> earlier
I'm going to ignore experimental.copytrace when changeset-centric
algorithms are required. This little refactoring makes that easier to
add.
Differential Revision: https://phab.mercurial-scm.org/D6268