DL: Fix metrics error message
diff --git a/src/ports/postgres/modules/deep_learning/madlib_keras_wrapper.py_in b/src/ports/postgres/modules/deep_learning/madlib_keras_wrapper.py_in
index e3f9f01..980bf69 100644
--- a/src/ports/postgres/modules/deep_learning/madlib_keras_wrapper.py_in
+++ b/src/ports/postgres/modules/deep_learning/madlib_keras_wrapper.py_in
@@ -196,8 +196,8 @@
         try:
             metrics = ast.literal_eval(compile_dict[ckey])
         except ValueError:
-            plpy.error(("Invalid input value for parameter {0}, "
-                        "please refer to the documentation").format(ckey))
+            plpy.error(("Invalid input value for parameter 'metric', "
+                        "please refer to the documentation"))
     return metrics
 
 def get_loss_from_compile_param(str_of_args):