chore(desktop): use different mechanism for second instance

apps/server/src/www.ts

@@ -55,24 +55,6 @@ export default async function startTriliumServer() {
     tmp.setGracefulCleanup();
 
     const app = await buildApp();
-
-    /**
-     * The intended behavior is to detect when a second instance is running, in that case open the old instance
-     * instead of the new one. This is complicated by the fact that it is possible to run multiple instances of Trilium
-     * if port and data dir are configured separately. This complication is the source of the following weird usage.
-     *
-     * The line below makes sure that the "second-instance" (process in window.ts) is fired. Normally it returns a boolean
-     * indicating whether another instance is running or not, but we ignore that and kill the app only based on the port conflict.
-     *
-     * A bit weird is that "second-instance" is triggered also on the valid usecases (different port/data dir) and
-     * focuses the existing window. But the new process is start as well and will steal the focus too, it will win, because
-     * its startup is slower than focusing the existing process/window. So in the end, it works out without having
-     * to do a complex evaluation.
-     */
-    if (utils.isElectron) {
-        (await import("electron")).app.requestSingleInstanceLock();
-    }
-
     const httpServer = startHttpServer(app);
 
     const sessionParser = (await import("./routes/session_parser.js")).default;