Fix NPE in region overlap check.

This commit fixes an issue with the new `intersects()` method on ArenaRegion. Instead of blindly assuming that the region points `p1` and `p2` are set when the method is called, we first make sure both regions are properly set.

Fixes #590

changelog.md

@@ -11,6 +11,7 @@ These changes will (most likely) be included in the next version.
 
 
 ## [Unreleased]
+- Arenas with missing regions no longer cause errors in the region overlap check.
 
 ## [0.104.1] - 2019-12-31
 - It is no longer necessary to have recurrent waves for an arena to work. MobArena automatically creates a "catch all" recurrent wave in case the arena session reaches a wave number that isn't covered by any other wave definitions.

src/main/java/com/garbagemule/MobArena/region/ArenaRegion.java

@@ -248,7 +248,10 @@ public class ArenaRegion
                 return true;
             }
         }
-        return intersects(p1, p2, other.p1, other.p2);
+        if (setup && other.setup) {
+            return intersects(p1, p2, other.p1, other.p2);
+        }
+        return false;
     }
 
     private boolean intersects(Location a1, Location a2, Location b1, Location b2) {