Made T2+ tanks instantly kill nodes

core/src/mindustry/world/Block.java

@@ -224,6 +224,8 @@ public class Block extends UnlockableContent implements Senseable{
     public float placeOverlapRange = 50f;
     /** Multiplier of damage dealt to this block by tanks. Does not apply to crawlers. */
     public float crushDamageMultiplier = 1f;
+    /** If true, this block is instantly destroyed by tanks with crushFragile set to true. */
+    public boolean crushFragile = false;
     /** Max of timers used. */
     public int timers = 0;
     /** Cache layer. Only used for 'cached' rendering. */