fixed database queries never completing on runtime errors

core/src/main/java/eu/mhsl/craftattack/spawn/core/database/Database.java

@@ -93,6 +93,8 @@ public class Database {
             } catch(SQLException e) {
                 this.closeConnection();
                 future.completeExceptionally(e);
+            } catch(RuntimeException e) {
+                future.completeExceptionally(e);
             }
         });
         return future;