Update error message test for split-by

The now deprecated split-by command produces different error messages
depending on whether the input is a value or a stream.

The `errors_if_non_record_input` test used to check whether the error
message produced was the one produced when the input is a value. This
commit updates this test so that is also accepts the error message
produced when the input is a stream.

crates/nu-command/tests/commands/split_by.rs

@@ -56,8 +56,11 @@ fn errors_if_non_record_input() {
             "
         ));
 
-        assert!(only_supports
+        assert!(
+            only_supports
                 .err
-            .contains("only Record input data is supported"));
+                .contains("only Record input data is supported")
+                || only_supports.err.contains("expected: record")
+        );
     })
 }