[OBMFULL-4871] - remove the row in opush_sync_perms with NULL policy in the first provision of a unknown device. For some client, unknown device is not automatically allowed. As an Admin of OBM, when i click on the partnership button to allow the new device, a new row is created in opush_sync_perms. This row is not treated by opush. It results in a duplicate entry in the device management view in obm-ui.

Conflicts:

	java/sync/opush/spushnik/src/test/java/org/obm/push/resources/FolderSyncScenarioTest.java