Fix typo in interfaces/spm/preprocess.py

	Concerning Normalise12:
	1- deformation_file and image_to_align are mutually exclusive. So we can't use the mandatory=True option for these two traits, as one of them will always be Undefined.
	2- the self.inputs.jobtype == "estimate" statement is useless because the jobtype trait can only take values in ["est", "write", "estwrite"].

nipype/interfaces/spm/preprocess.py

@@ -1290,7 +1290,6 @@ class Normalize12InputSpec(SPMCommandInputSpec):
         field="subj.vol",
         desc=("file to estimate normalization parameters with"),
         xor=["deformation_file"],
-        mandatory=True,
         copyfile=True,
     )
     apply_to_files = InputMultiPath(
@@ -1303,7 +1302,6 @@ class Normalize12InputSpec(SPMCommandInputSpec):
     )
     deformation_file = ImageFileSPM(
         field="subj.def",
-        mandatory=True,
         xor=["image_to_align", "tpm"],
         copyfile=False,
         desc=(
@@ -1485,13 +1483,7 @@ def _list_outputs(self):
                 outputs["deformation_field"].append(fname_presuffix(imgf, prefix="y_"))
             outputs["deformation_field"] = simplify_list(outputs["deformation_field"])
 
-        if self.inputs.jobtype == "estimate":
-            if isdefined(self.inputs.apply_to_files):
-                outputs["normalized_files"] = self.inputs.apply_to_files
-            outputs["normalized_image"] = fname_presuffix(
-                self.inputs.image_to_align, prefix="w"
-            )
-        elif "write" in self.inputs.jobtype:
+        if "write" in self.inputs.jobtype:
             outputs["normalized_files"] = []
             if isdefined(self.inputs.apply_to_files):
                 filelist = ensure_list(self.inputs.apply_to_files)