BUG: fix initial state covariance
BUG: fix initial state covariance

SiLab-Bonn/testbeam_analysis,YannickDieter/testbeam_analysis,SiLab-Bonn/testbeam_analysis,YannickDieter/testbeam_analysis,YannickDieter/testbeam_analysis,SiLab-Bonn/testbeam_analysis,SiLab-Bonn/testbeam_analysis,YannickDieter/testbeam_analysis