[Fix] Bracket it if IPv6 address
[Fix] Bracket it if IPv6 address

Fix for a part of pull request #264.

sta/websocket-sharp,sta/websocket-sharp,jogibear9988/websocket-sharp,sta/websocket-sharp,sta/websocket-sharp,jogibear9988/websocket-sharp,2Toad/websocket-sharp,2Toad/websocket-sharp,2Toad/websocket-sharp,jogibear9988/websocket-sharp,2Toad/websocket-sharp,jogibear9988/websocket-sharp