fix values of FTDecayFunctionVoigt 1D & 2D
1D: without the fix m_eta refers to the same as m_decay_length => calculations will be wrong
2D: without the fix m_eta refers to the same as m_decay_length_x => calculations will be wrong
2D: the ctor values have been in wrong order => clone will be wrongly initialized
Edited by m.puchner