Fix SOFA Import Degree Handling

[Firionus]

The current SOFA import code results in a right shift of most sources by about 6 degrees and some holes/instability, since the SOFA azimuth in degrees is wrapped by 2*pi as if it were in rad:

I removed the corresponding lines. Since they are purely re-assigning, there is no impact on the surrounding code.

While you look at the code, please also evaluate whether the exact same lines are needed for the switch case above. sph2cart seems to consist of some simple statements with sines/cosines which should work regardless of angle range. But I don't have an FRL_HRTF file to test that.