Actually assign the queried version to a variable

The Floodgate version was queried, but it's return value wasn't actually assigned to a variable.

Edited this from mobile GitHub website. I have no code check here.

Author: Smart123s

bungee/src/main/java/com/github/games647/fastlogin/bungee/FastLoginBungee.java

@@ -92,7 +92,7 @@ public void onEnable() {
         String floodgateVersion = "0";
         Plugin floodgatePlugin = pluginManager.getPlugin("floodgate");
         if (floodgatePlugin != null) {
-            floodgatePlugin.getDescription().getVersion();
+            floodgateVersion = floodgatePlugin.getDescription().getVersion();
         }
 
         ConnectListener connectListener = new ConnectListener(this, core.getRateLimiter(), floodgateVersion);