Fix unsupported type message for some math related commands (#4672)

* Fix unsupported type message of some math related commands

* changing the error form for UnsupportedInput

* cargo fmt

crates/nu-command/src/env/load_env.rs

@@ -75,7 +75,10 @@ impl Command for LoadEnv {
                     }
                     Ok(PipelineData::new(call.head))
                 }
-                _ => Err(ShellError::UnsupportedInput("Record".into(), span)),
+                _ => Err(ShellError::UnsupportedInput(
+                    "Record not supported".into(),
+                    span,
+                )),
             },
         }
     }