Small fix.

nodes.py

@@ -752,7 +752,7 @@ class SaveImage:
 
         if os.path.commonpath((self.output_dir, os.path.realpath(full_output_folder))) != self.output_dir:
             print("Saving image outside the output folder is not allowed.")
-            return
+            return {}
 
         try:
             counter = max(filter(lambda a: a[1][:-1] == filename and a[1][-1] == "_", map(map_filename, os.listdir(full_output_folder))))[0] + 1