match: fix re2 compability broken in 2e2699af5649
When using re2, we call test_match() instead of match() on the
compiled regex object. While match() returns a matcher object or None,
test_match() returns True or False. So since 2e2699af5649 running test
on a machine with a re2 install fails in many places. Instead we make
the code a bit more general and everything goes back to normal.