Let the chatarea expand when the occupants sidebar is collapsed.

src/templates/chatarea.html

@@ -1,4 +1,4 @@
-<div class="chat-area col-md-9 col-8">
+<div class="chat-area col">
     <div class="chat-content {[ if (o.show_send_button) { ]}chat-content-sendbutton{[ } ]}"></div>
     <div class="new-msgs-indicator hidden">▼ {{{ o.unread_msgs }}} ▼</div>
     <form class="sendXMPPMessage">