Implemented automatic co-op sector change sync

core/src/mindustry/content/Planets.java

@@ -9,6 +9,7 @@ import mindustry.type.*;
 public class Planets implements ContentList{
     public static Planet
     sun,
+    //tantros,
     serpulo;
 
     @Override
@@ -32,6 +33,17 @@ public class Planets implements ContentList{
             );
         }};
 
+        /*tantros = new Planet("tantros", sun, 2, 0.8f){{
+            generator = new TantrosPlanetGenerator();
+            meshLoader = () -> new HexMesh(this, 4);
+            atmosphereColor = Color.valueOf("3db899");
+            startSector = 10;
+            atmosphereRadIn = -0.01f;
+            atmosphereRadOut = 0.3f;
+            accessible = false;
+            visible = false;
+        }};*/
+
         serpulo = new Planet("serpulo", sun, 3, 1){{
             generator = new SerpuloPlanetGenerator();
             meshLoader = () -> new HexMesh(this, 6);