Remove enter-to-autocomplete

see http://sonohara.donmai.us/forum_topics/10558

vendor/assets/javascripts/jquery-ui-autocomplete-custom.js

@@ -116,17 +116,6 @@ $.widget( "ui.autocomplete", {
           suppressKeyPress = true;
           this._keyEvent( "next", event );
           break;
-        case keyCode.ENTER:
-        case keyCode.NUMPAD_ENTER:
-          // when menu is open and has focus
-          if ( this.menu.active ) {
-            // #6055 - Opera still allows the keypress to occur
-            // which causes forms to submit
-            suppressKeyPress = true;
-            event.preventDefault();
-            this.menu.select( event );
-          }
-          break;
         case keyCode.TAB:
           if ( this.menu.active ) {
             event.preventDefault();