_extractldif function bugfix

Hello.

Got a problem, while trying to run ldapaddusertogroup command. It said, that user was added to the group successfully, but it wasn't. After some debugging, I found out, that extractldif function fails at the grep line, because cannot find ldapaddusertogroup script to parse.

I replaced that line with:
grep "^#\{$_EXTRACTDEPTH\}[^#]*$" which $0 | sed 's|^#*||' 2>>"$LOGFILE"
which resolved the problem.

Some additional information: Ubuntu 14.04, ldapscripts package was installed from the base repository, path to script: /usr/bin/ldapaddusertogroup is in $PATH as well.