Improve logging on config loading failures.

When we fail to load a config directory we are logging that
it wasn't a directory. With this change also log which directory
we were expecting to load that isn't one so we can fix it...

src/daemon/config.rs

@@ -114,7 +114,8 @@ async fn read_config_directory<P: AsRef<Path> + Sync + Send>(
                 );
                 return Ok(builder);
             }
-            error!("Error reading config fragment directory: {e}");
+            error!("Error reading config fragment directory {}: {e}",
+                path.as_ref().to_string_lossy());
             return Err(e.into());
         }
     };