Prevent KeyError for AD if only zero/one feature bands exist (#376)

* Uninstall onnx to see if this is neceaasy

* Fix test

* Prevent KeyError if only one/zero band exist

* Clean

fink_science/anomaly_detection/processor.py

@@ -120,7 +120,7 @@ def get_key(x, band):
                 )
             )
         ):
-            return pd.Series({}, dtype=np.float64)
+            return pd.Series({k: np.nan for k in MODEL_COLUMNS}, dtype=np.float64)
         else:
             return pd.Series(x[band])