Fix interp enum value for RegResample and RegTools

According to NiftyReg source code:
https://cmiclab.cs.ucl.ac.uk/mmodat/niftyreg/blob/master/reg-apps/reg_resample.cpp#L65

Author: fepegar

nipype/interfaces/niftyreg/regutils.py

@@ -122,7 +122,7 @@ class RegResample(NiftyRegCommand):
     # Need this overload to properly constraint the interpolation type input
     def _format_arg(self, name, spec, value):
         if name == 'inter_val':
-            inter_val = {'NN': 0, 'LIN': 1, 'CUB': 3, 'SINC': 5}
+            inter_val = {'NN': 0, 'LIN': 1, 'CUB': 3, 'SINC': 4}
             return spec.argstr % inter_val[value]
         else:
             return super(RegResample, self)._format_arg(name, spec, value)
@@ -338,7 +338,7 @@ class RegTools(NiftyRegCommand):
     # Need this overload to properly constraint the interpolation type input
     def _format_arg(self, name, spec, value):
         if name == 'inter_val':
-            inter_val = {'NN': 0, 'LIN': 1, 'CUB': 3, 'SINC': 5}
+            inter_val = {'NN': 0, 'LIN': 1, 'CUB': 3, 'SINC': 4}
             return spec.argstr % inter_val[value]
         else:
             return super(RegTools, self)._format_arg(name, spec, value)