irc: remove duplicate NICK handler in handleLine

Signed-off-by: Slendi <slendi@socopon.com>

main.lua

@@ -656,14 +656,6 @@ function IrcChatView:handleLine(line)
                 end
             end
             return
-        elseif command == "NICK" then -- someone changed nick; update ours if it's us
-            local newnick = rest:match("^:(.+)$") or rest
-            local oldnick = prefix:match("^([^!]+)!") or prefix
-            if oldnick == self._nick and newnick and #newnick > 0 then
-                self._nick = newnick
-                self:appendLine(T(_("You are now known as %1"), newnick))
-            end
-            return
         elseif command == "376" or command == "422" then
             -- End of MOTD / No MOTD: safe to join if not yet joined
             if not self._registered then self._registered = true end