Fix doSegmentT0Fit handling in MuonSegmentFindingConfig for cosmics

Some inconsistency in the doSegmentT0Fit configuration in the muon CA config was spotted following investigations related to ATLASRECTS-7331. Minimal changes are applied to be able to run the cosmics reconstruction. The DCMathSegmentMakerCfg probably needs some follow-up but left for future update as it increases difference with legacy config, so this needs to be understood in more details first.

Checked to keep q445 outputs unchanged