Ticket 47752 - Don't add unhashed password mod if we don't have an unhashed value
When performing a modify operation to replace the userpassword with a pre-hashed
value, the modify code adds a LDAPMod that replaces the "unhashed#user#password"
attribute with no values. While this doesn't cause any harm inside DS itself, it
is not the correct behavior. We should only add a LDAPMod for the unhashed password
if we actually have an unhashed value available.
https://fedorahosted.org/389/ticket/47752
Reviewed by mreynold@redhat.com