(ITS#8285) RFE slapo-ppolicy: fall back to createTimestamp

[michael@stroeder.com]

Full_Name: Michael Str.der
Version: 
OS: 
URL: 
Submission from: (NULL) (213.240.180.113)


If pwdMaxAge is set in a pwdPolicy entry but the user's entry does not contain
pwdChangedTime attribute createTimestamp should be used instead to determine
whether password is expired or not.

The case above can happen if there are already existing entries with
userPassword and slapo-ppolicy gets installed and activated later.