Terminate gql subscription on server address change

Otherwise, the subscription is still active for the old server instead of connecting to the new server

src/lib/requests/client/BaseClient.ts

@@ -9,14 +9,10 @@
 import { AppStorage } from '@/util/AppStorage.ts';
 
 export abstract class BaseClient<Client, ClientConfig, Fetcher> {
-    protected client!: Client;
+    protected abstract client: Client;
 
     public abstract readonly fetcher: Fetcher;
 
-    constructor() {
-        this.createClient();
-    }
-
     public getBaseUrl(): string {
         const { hostname, port, protocol } = window.location;
 
@@ -25,7 +21,5 @@ export abstract class BaseClient<Client, ClientConfig, Fetcher> {
         return AppStorage.local.getItemParsed('serverBaseURL', `${protocol}//${hostname}:${inferredPort}`);
     }
 
-    protected abstract createClient(): void;
-
     public abstract updateConfig(config: Partial<ClientConfig>): void;
 }