overflowHidden causes page to jump
overflowHidden causes page to jump

- when the purchasing modal appeared, the page would jump horizontally
because the scrollbar disappeared when overflow Y hidden was added.

That property doesn't seem to be needed, so the overflow class was
removed.

rmisio/OpenBazaar-Client,mariodian/OpenBazaar-Client,blockchainProject/blockchain-project-client,blockchainProject/blockchain-project-client,OpenBazaar/OpenBazaar-Client,OpenBazaar/OpenBazaar-Client,mariodian/OpenBazaar-Client,rmisio/OpenBazaar-Client,jjeffryes/OpenBazaar-Client,jjeffryes/OpenBazaar-Client