Enhance accounts_password_pam_dcredit.sh

The previous solution would truncate everything after (dcredit *= *\) if dcredit was not the last config entry on the line.

example line:
password    requisite     pam_cracklib.so try_first_pass retry=3 difok=3 minlen=14 ucredit=-1 ocredit=-1 dcredit=-1 lcredit=-1

Proposed solution replaces setting in place no matter where it is in the config line