The ASN.1 parser for a date-time had to check the date-time string was
all digits to catch the case of a sign in the month field, which used
to be accepted when it should not be. That bug has now been fixed, so
remove the work-around and add a second date-time test-case, renaming
(and modernising) the existing one for consistency.
Task-number: QTBUG-84349
Change-Id: I649c5129312b6865af08b22ba6893cb4e29243f8
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>