Martin von Zweigbergk <martinvonz@google.com> [Fri, 12 Jul 2019 23:00:11 -0700] rev 4734
cleanup: remove check only needed for hg versions before 4.4
ui.edit() has had the "action" argument since 6e6452bc441d (editor:
use an unambiguous path suffix for editor files, 2017-08-30), which
was first released in hg version 4.4. Since we support only versions
higher than 4.5, we can drop this check.