Fix compilation warnings under gcc13 and clang16

Summary:
Fix compilation warnings under gcc13 and clang16

Additionally fix FSR options in one test JSON file

Test Plan: All tests give identical results

Reviewers: jback, abudinen, kreps

Reviewed By: abudinen

Subscribers: #evtgen_admins

Tags: #evtgen

Differential Revision: https://phab.hepforge.org/D122