Fix port bug

src/discordas.ts

@@ -129,10 +129,6 @@ async function run() {
     }
 
     const config = new DiscordBridgeConfig();
-    const port = opts.port || config.bridge.port;
-    if (!port) {
-        throw Error("Port not given in command line or config file");
-    }
     const readConfig = yaml.safeLoad(fs.readFileSync(configPath, "utf8"));
     if (typeof readConfig !== "object") {
         throw Error("Config is not of type object");
@@ -140,6 +136,10 @@ async function run() {
     config.applyConfig(readConfig);
     config.applyEnvironmentOverrides(process.env);
     Log.Configure(config.logging);
+    const port = opts.port || config.bridge.port;
+    if (!port) {
+        throw Error("Port not given in command line or config file");
+    }
     if (config.database.roomStorePath || config.database.userStorePath) {
         log.error("The keys 'roomStorePath' and/or 'userStorePath' is still defined in the config. " +
                   "Please see docs/bridge-migrations.md on " +