Fix BTaggingTruthTool Not Initializing Correctly with DL1 Configuration

Currently, BTaggingTruthTool doesn't set MinPt for its efficiencyTool. This causes a problem if the Tagger is set as DL1, here: https://acode-browser1.usatlas.bnl.gov/lxr/source/athena/PhysicsAnalysis/JetTagging/JetTagPerformanceCalibration/xAODBTaggingEfficiency/Root/BTaggingEfficiencyTool.cxx?v=21.2#0491

What happens is that when the efficiencyTool initializes, it tries to create a selection tool with its own minPt with a default value of -1. This causes an error in the initialization of the selection tool, and returns an error.

This change should fix that error.