dirmngr: Improve LDAP debug output.
* dirmngr/dirmngr.h (DBG_LDAP_VALUE, DBG_LDAP): New value and macro. * dirmngr/dirmngr.c (debug_flags): Add "ldap". * dirmngr/ks-engine-ldap.c: Improve debug output and use the new debug flag instead of any debug value.