Fix Zalcano damage overlay to only show during Zalcano

This varp is for the hp hud, and applies to more content than just
Zalcano, so verify that the hp hud is for Zalcano

runelite-client/src/main/java/net/runelite/client/plugins/zalcano/ZalcanoPlugin.java

@@ -265,6 +265,7 @@ public class ZalcanoPlugin extends Plugin
 
 	private boolean isHealthbarActive()
 	{
-		return client.getVar(VarPlayer.ZALCANO_FORM) != -1;
+		int npcId = client.getVar(VarPlayer.HP_HUD_NPC_ID);
+		return npcId == ZALCANO_WEAKENED || npcId == ZALCANO;
 	}
 }