yaml-import: fix working with deleted data
yaml-import: fix working with deleted data

At some cases, ir.model.data is left with orphan entries, so ensure that
the message below is used (rather than "bool has no get()" exception).

Conflicts:

	bin/tools/yaml_import.py


akretion/openerp-server,akretion/openerp-server,akretion/openerp-server