Update Drone to only build on main branch

.drone.yml

@@ -7,3 +7,6 @@ steps:
     commands:
       - mvn install -DskipTests=true -Dmaven.javadoc.skip=true -B -V
       - mvn test -B
+    when:
+      branch:
+        - main

src/main/java/wtf/beatrice/uhccore/UhcCore.java

@@ -34,6 +34,7 @@ public class UhcCore extends JavaPlugin
 
         // We need to run this in a task, because the plugin has to be initialized AFTER all the worlds are loaded.
         // todo: after a few months, this sounds like a badly implemented idea
+        // ^ i agree, why the hell is this happening?
         getServer().getScheduler().runTask(this, ()->
         {