GammaLib

In GModelSpectralLogParabola a bug occurred in the function update_eval_cache().
In line 963 of GModelSpectralLogParabola.cpp m_last_power is calculated to

m_last_exponent   = m_last_index + m_last_curvature * m_last_log_e_norm;
m_last_power      = std::pow(m_last_e_norm, m_last_index);

in the eval() and eval_gradient()-methods, the function value is then calculated by:
double value = m_norm.value() * m_last_power;
However, this only returns the power law value without any curvature. The correct line of code in line 963 should be:

m_last_power      = std::pow(m_last_e_norm, m_last_exponent);

Is it worth to create a feature branch for changing one word?