Fixed some claims not being completely deleted.

src/me/ryanhamshire/GriefPrevention/DataStore.java

@@ -582,6 +582,8 @@ public abstract class DataStore
         for(Long chunkHash : chunkHashes)
         {
             ArrayList<Claim> claimsInChunk = this.chunksToClaimsMap.get(chunkHash);
+            if(claimsInChunk != null)
+            {
                 for(int j = 0; j < claimsInChunk.size(); j++)
                 {
                     if(claimsInChunk.get(j).id.equals(claim.id))
@@ -590,6 +592,7 @@ public abstract class DataStore
                         break;
                     }
                 }
+            }
         }
 		
 		//remove from secondary storage