undone some changes that were not needed

Fabio Bernardoni · Fabio Bernardoni · commit adea98ea69db · 2022-09-01T15:04:24.000+02:00
diff --git a/nipype/interfaces/spm/preprocess.py b/nipype/interfaces/spm/preprocess.py
@@ -258,9 +258,7 @@ def _list_outputs(self):
 class ApplyVDMInputSpec(SPMCommandInputSpec):
 
     in_files = InputMultiObject(
-        traits.Either(
-            ImageFileSPM(exists=True), traits.List(ImageFileSPM(exists=True))
-        ),
+        ImageFileSPM(exists=True),
         field='data.scans',
         mandatory=True,
         copyfile=True,
