Bug in RungeKuttaEngine in propgate() of charged parameters (was ACTS-297)

Original author Julia Hrdinka @jhrdinka

In the propagate function of charged parameters in the RungeKuttaEngine when the parameters are already on the surface a segfault occurs. In this case the new parameters 'pParameters' (which are set to nullptr at initialization) should be created from the given 'sParameters', which are the current lead parameters. Instead 'pParameters' are dereferenced which creates the segmentation fault: https://gitlab.cern.ch/acts/a-common-tracking-sw/blob/master/Core/include/ACTS/Extrapolation/detail/RungeKuttaEngine.ipp#L354