tests: adjust to the new format in pyflakes output

According to the pyflakes' NEWS.rst, the default output format changed
recently:

  2.2.0 (2020-04-08)
  - Include column information in error messages

So the lines now read:

  contrib/perf.py:149:15 undefined name 'xrange'
  mercurial/hgweb/server.py:427:13 undefined name 'reload'
  mercurial/util.py:2862:24 undefined name 'file'

This is a graft of a similar fix that ended up on default.

Differential Revision: https://phab.mercurial-scm.org/D8630

tests/test-check-pyflakes.t

@@ -9,7 +9,7 b' run pyflakes on all tracked files ending'
   > print(undefinedname)
   > EOF
   $ $PYTHON -m pyflakes test.py 2>/dev/null | "$TESTDIR/filterpyflakes.py"
-  test.py:1: undefined name 'undefinedname'
+  test.py:1:* undefined name 'undefinedname' (glob)
   
   $ cd "`dirname "$TESTDIR"`"
 
@@ -19,8 +19,8 b' run pyflakes on all tracked files ending'
   > -X mercurial/thirdparty \
   > 2>/dev/null \
   > | xargs $PYTHON -m pyflakes 2>/dev/null | "$TESTDIR/filterpyflakes.py"
-  contrib/perf.py:*: undefined name 'xrange' (glob) (?)
-  mercurial/hgweb/server.py:*: undefined name 'reload' (glob) (?)
-  mercurial/util.py:*: undefined name 'file' (glob) (?)
-  mercurial/encoding.py:*: undefined name 'localstr' (glob) (?)
+  contrib/perf.py:*:* undefined name 'xrange' (glob) (?)
+  mercurial/hgweb/server.py:*:* undefined name 'reload' (glob) (?)
+  mercurial/util.py:*:* undefined name 'file' (glob) (?)
+  mercurial/encoding.py:*:* undefined name 'localstr' (glob) (?)