Fix network layout displaying the scrollbar incorrectly

This was introduced by https://github.com/thelounge/lounge/pull/856/files#diff-97db1f70168fb5f12457b238ff6052b5R773 (and L794-798): a right position got introduced for all channel containers, but default position for other types of containers was absent before this script.

client/css/style.css

@@ -762,6 +762,7 @@ kbd {
 #chat .chat {
 	bottom: 0;
 	left: 0;
+	right: 0;
 	overflow: auto;
 	-webkit-overflow-scrolling: touch;
 	position: absolute;