PressureTests: Fix two tests due to bad test constants
PressureTests: Fix two tests due to bad test constants

Implementation was right, test was wrong

BrandonLWhite/UnitsNet,Tirael/UnitsNet,BrandonLWhite/UnitsNet,anjdreas/UnitsNet,neutmute/UnitsNet,BoGrevyDynatest/UnitsNet,anjdreas/UnitsNet