[Qt] ensure socket is set to NULL in PaymentServer::ipcSendCommandLine
[Qt] ensure socket is set to NULL in PaymentServer::ipcSendCommandLine

(cherry picked from commit 1ec753f7340677ac4fbef53fbdc73feff344719d)

reddcoin-project/reddcoin,reddcoin-project/reddcoin,reddcoin-project/reddcoin,reddcoin-project/reddcoin,reddcoin-project/reddcoin,reddcoin-project/reddcoin