L1uGTTreeProducer is quite spammy when running on MC

[dinyar]

When running on MC the L1uGTTreeProducer is instantiated both for the uGT as well as for the uGT testcrate (trying to fill the l1uGTTestcrateTree). As there is no uGT testcrate emulator this fails and we get a warning for every event:

Begin processing the 98036th record. Run 1, Event 3273039, LumiSection 3274 on stream 0 at 12-Apr-2023 19:12:50.910 CEST
%MSG-w MissingProduct:  L1uGTTreeProducer:l1uGTTestcrateTree  12-Apr-2023 19:12:51 CEST Run: 1 Event: 3273039
L1uGTTree or L1uGTTestcrateTree GlobalAlgBlkBxCollection not found. Branch will not be filled.
Please note that the L1uGTTestcrateTree is not expected to exist in MC, so this warning can be ignored!

It would be nice if this could be silenced, I'll try to look into it myself, but if others have ideas those would be appreciated.

-d