run-tests: fix broken regular expression

The regular expression in use passed tests because the test repo only
has single-digit changesets present. When I tried to use this for real
today, it broke, because the regular expression would only match a
single digit.

https://xkcd.com/1171/, or something like that.

tests/run-tests.py

@@ -1864,7 +1864,7 b' class TextTestRunner(unittest.TextTestRu'
                     sub.wait()
                     m = re.search(
                         (r'\nThe first (?P<goodbad>bad|good) revision '
-                         r'is:\nchangeset: +\d:(?P<node>[a-f0-9]+)\n.*\n'
+                         r'is:\nchangeset: +\d+:(?P<node>[a-f0-9]+)\n.*\n'
                          r'summary: +(?P<summary>[^\n]+)\n'),
                         data, (re.MULTILINE | re.DOTALL))
                     if m is None: