Fix stuff

(cherry picked from commit 2727a82777)

src/de/steamwar/towerrun/generator/TowerGenerator.java

@@ -42,7 +42,7 @@ public class TowerGenerator {
     }
 
     public TowerGenerator(int x, int y, int z, SchematicType schematicType) {
-        File file = new File(Bukkit.getWorlds().get(0).getWorldFolder(), "Roof.schematic");
+        File file = new File(Bukkit.getWorlds().get(0).getWorldFolder(), "Roof.schem");
         if (!file.exists()) {
             Bukkit.shutdown();
             return;