Automatically put people into DTTHDon login

src/pages/login.jsx

@@ -23,7 +23,7 @@ function Login() {
   const instance = searchParams.get('instance');
   const submit = searchParams.get('submit');
   const [instanceText, setInstanceText] = useState(
-    instance || cachedInstanceURL?.toLowerCase() || '',
+    instance || cachedInstanceURL?.toLowerCase() || 'gts.dtth.ch',
   );
 
   const [instancesList, setInstancesList] = useState([]);
@@ -33,6 +33,9 @@ function Login() {
         const res = await fetch(instancesListURL);
         const data = await res.json();
         setInstancesList(data);
+
+        // Automatically just login to DTTHDon
+        submitInstance("gts.dtth.ch")
       } catch (e) {
         // Silently fail
         console.error(e);