d/control: make libldap2 depend on libldap-common

This chanage reverts a workaround [1] for a bug in the Debian Archive Kit (dak) [2].

Installing packages which depend on libldap2 with --no-install-recommends will not install the libldap-common package. This may result in unexpected behaviors when libldap2 code paths are triggered due to a missing reference to the trusted CAs certificates, which is defined by the configuration file shipped in libldap-common.

Since the dak bug affects several other packages, this should, ideally, be fixed in dak.

This was originally reported in Ubuntu [3] due to a bug found after a user installed the php-ldap package.

[1] 567d8d6d [2] bugs.debian.org/cgi-bin/bugreport.cgi?bug=915948 [3] https://bugs.launchpad.net/ubuntu/+source/php-defaults/+bug/2063161