Fixed many various things

core/src/io/anuke/mindustry/maps/Sectors.java

@@ -41,7 +41,7 @@ public class Sectors{
     private final AsyncExecutor executor = new AsyncExecutor(6);
 
     public void playSector(Sector sector){
-        if(sector.hasSave() && SaveIO.breakingVersions.contains(sector.getSave().getBuild())){
+        if(!headless && sector.hasSave() && SaveIO.breakingVersions.contains(sector.getSave().getBuild())){
             sector.getSave().delete();
             ui.showInfo("$text.save.old");
         }

core/src/io/anuke/mindustry/maps/missions/MessageMission.java

@@ -1,15 +0,0 @@
-package io.anuke.mindustry.maps.missions;
-
-import io.anuke.mindustry.Vars;
-
-/**A mission that just displays some text.*/
-public class MessageMission extends ActionMission{
-
-    public MessageMission(String text){
-        super(() -> {
-            if(!Vars.headless){
-                Vars.ui.showInfo(text);
-            }
-        });
-    }
-}