index: disable input bar autocompletion

The autocompletion support on the input bar is global, which makes no
sense to use.

index.html

@@ -191,7 +191,7 @@
       <div class="navbar navbar-inverse navbar-fixed-bottom">
         <form class="form form-horizontal" ng-submit="sendMessage()">
           <div class="input-group">
-            <input id="sendMessage" type="text" class="form-control" ng-model="command" autofocus>
+            <input id="sendMessage" type="text" class="form-control" autocomplete="off" ng-model="command" autofocus>
             <span class="input-group-btn">
               <button class="btn btn-default btn-primary">Send</button>
             </span>