restart required ex.code 101->201

rust panic returns 101, so this wasn't a good choice

README.md

@@ -11,4 +11,4 @@
 - ```skip-launcher-update``` skips self-update
 
 ### Note for server owners:
-When the launcher updates itself it needs to be restarted. It will return exit code 101 in this case.
+When the launcher updates itself it needs to be restarted. It will return exit code 201 in this case.

src/main.rs

@@ -109,7 +109,7 @@ fn self_update(update_only: bool) {
         if !update_only {
             std::io::stdin().read_line(&mut String::new()).unwrap();
         }
-        std::process::exit(101);
+        std::process::exit(201);
     }
 }