Correct documentation URL for afni.Bandpass

[alexsavio]

Hi,

The correct URL for Bandpass is:
https://afni.nimh.nih.gov/pub/dist/doc/program_help/3dBandpass.html

The URL is wrong here:
http://nipy.org/nipype/interfaces/generated/nipype.interfaces.afni.preprocess.html#bandpass

I can fix this later, if nobody else does.

[alexsavio]

The same happens for:
https://afni.nimh.nih.gov/pub/dist/doc/program_help/3dFourier.html