Update IRC channel in CONTRIBUTING.md
Update IRC channel in CONTRIBUTING.md

ptMuta/sway,taiyu-len/sway,4e554c4c/sway,ascent12/sway,SirCmpwn/sway,ascent12/sway,1ace/sway,ascent12/sway,4e554c4c/sway,1ace/sway,taiyu-len/sway,taiyu-len/sway,1ace/sway,johalun/sway