#207839 Missed removing one of the hook_requirements that is no longer needed...

#207839 Missed removing one of the hook_requirements that is no longer needed now that we use hook_last_update.

Also, since we now know we cannot assume the content module update has run before a field module will need the fields info, revert back to an earlier version of content_install_types() that will work even if the node_fields table has not been updated.