css tweaks. Don't show scrollbar by default

converse.css

@@ -421,7 +421,7 @@ form.search-xmpp-contact input {
 
 #converse-roster {
     height: 200px;
-    overflow-y: scroll;
+    overflow-y: auto;
     width: 100%;
     margin: 0;
     position: relative;
@@ -481,7 +481,7 @@ dd.available-chatroom,
 }
 
 #converse-roster  dd:hover *[class*="open-chat"] {
-    width: 128px;
+    width: 75%;
 }
 
 .chatbox,