Chat button is disabled for the offer maker for a Buy XEC offer

[nghiacc]

For Buy XEC offers (maker offers to Buy XEC), when the taker place an order, the Chat with Seller is not enable. Howver the taker can chat the Buyer's (maker).
Expected: it should be enabled for maker (Buyer) and disabled for taker (Seller).
When the maker (Buyer) chat with the taker the taker will also be able to see the button enabled too to chat with maker (buyer).

The flow for Sell XEC should be kept as is.