Some broken subversion server gives timestamps with only one digit
in the hour part, like this:

    2014-01-07T5:01:02.048176Z

Loosen the regexp that expected to see two-digit hour, minute and
second parts to accept a single-digit hour (but not minute or
second).
Signed-off-by: NStepan Kasal <kasal@ucw.cz>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>