Modify ldap autoconf function, so that an incorrect ldap library is not found...

Modify ldap autoconf function, so that an incorrect ldap library is not found on Solaris (it is incompatible).
Also removes second check for awk, which causes Solaris to find an incompatible version of awk.

(closes issue #11829)
Reported by: snuffy
Patches:
      bug-11829.diff uploaded by snuffy (license 35)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@103694 65c4cc65-6c06-0410-ace0-fbb531ad65f3