ubuntu: Exclude numpy deps from shared dependencies and pin setuptools for xenial

[mamedin]

This PR fixes python issues when building AM1.12 packages for Ubuntu:

• excludes numpy deps from shared dependencies.
• pins setuptools version for xenial packages.
• Restore SS ldap support por Ubuntu (and removes the problematic patch, see https://github.com/artefactual-labs/am-packbuild/issues/284)

Connects to https://github.com/artefactual-labs/am-packbuild/issues/282 ,https://github.com/archivematica/Issues/issues/1299 and https://github.com/artefactual-labs/am-packbuild/issues/284

[mamedin]

WIP, because ubuntu SS packages are still failing (python-ldap).