Resolved the traceback from yml while installing project_timesheet module in blank database

Installing the "project_timesheet" module in a blank database, causes an error as the product creation in yml makes reference to the "supply_method" field from the "procurement" module, but this module is not in the dependency.

Steps to reproduce:
1. Create a new database (preference with demo data)
2. Install the module "project_timesheet"
3. Be sure that you have enable the test yaml

Gives error : KeyError: "Object '' does not contain field 'supply_method'"