John cares not one whit how many colons are in a hash line, only that
there are enough for the format (at least 2 for regular /etc/passwd, at
least 3 for NTLM, etc). So there is no simple way to programmatically
determine whether a password had a colon or there was just an extra on
the end of the original hash line.
[MSP-9778]
See #2515