Cobblestone Walls too hard to break in survival

Put the summary of the bug you're having here

What I expected to happen was...: I expected the Cobblestone Wall to break as easily as other cobblestone items.

*What actually happened was...: The Cobblestone Wall was harder to break with an Iron Pickaxe than a Dirt block with hands.

Steps to Reproduce:
1. Place a Cobblestone Wall.
2. Break it with an Iron Pickaxe.