fix #76

Author: GeorgeRNG

src/main/java/dev/dfonline/codeclient/CodeClient.java

@@ -75,6 +75,7 @@ public static <T extends PacketListener> boolean handlePacket(Packet<T> packet)
 
         if (CodeClient.location instanceof Dev dev &&
                 packet instanceof BlockEntityUpdateS2CPacket beu &&
+                dev.isInDev(beu.getPos()) &&
                 MC.world != null &&
                 MC.world.getBlockEntity(beu.getPos()) instanceof SignBlockEntity) {
             dev.clearLineStarterCache();