[server/sources] fix name error in eid_type_source_pre_131
i.e. the eid_type_source implementation used when some pre 3.13.1
database is detected. Regression from 5fbdbbe51867.
# -*- coding: utf-8 -*-
# copyright %(year)s %(author)s, all rights reserved.
# contact %(author-web-site)s -- mailto:%(author-email)s
#
%(long-license)s
"""%(distname)s entity's classes"""