FIX: Copy num_threads to MapNode-generated Nodes

Author: effigies

nipype/pipeline/engine/nodes.py

@@ -1118,6 +1118,7 @@ def _make_nodes(self, cwd=None):
             node.plugin_args = self.plugin_args
             node._interface.inputs.set(
                 **deepcopy(self._interface.inputs.get()))
+            node._interface.num_threads = self._interface.num_threads
             for field in self.iterfield:
                 if self.nested:
                     fieldvals = flatten(filename_to_list(getattr(self.inputs, field)))