Fixes some Clippy remarks.

gamenight-cli/src/flows/main.rs

@@ -15,11 +15,17 @@ impl Main {
         main_menu.menu.push(Box::new(Exit::new()));
         Self {
             login: Box::new(Login::new()),
-            main_menu: main_menu
+            main_menu
         }
     }
 }
 
+impl Default for Main {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 #[async_trait]
 impl<'a> Flow<'a> for Main {
     async fn run(&self, state: &'a mut GamenightState) -> FlowResult<'a> {