be less strict in product renames

do not check the migration product as it can have different
name in SP2 and SP3, more over it might not be present when using
custom migration) (bnc#800515)
2.17.37
Merge remote-tracking branch 'origin/Code-11-SP3' into product_rename_bnc800515

Conflicts:
	package/yast2-wagon.changes
Merge pull request #6 from yast/product_rename_bnc800515

Be less strict in product renames (bnc#800515)