Demote warning on use of latest DB tags

Currently, when CondDB.LatestGlobalTagByDataType(s) is set in options, the following warning is emitted unconditionally:

 # WARNING: Default global tags will be overridden with the latest ones available for 'Upgrade' data type: {'DDDB': 'upgrade/dddb-20200529', 'SIMCOND': 'upgrade/sim-20200515-vc-md100'}

Here, this is demoted to INFO since the message is the result of explicitly using an option (so the user shouldn't need to be warned).

This issue exposed by Rec!2141 (merged)