make it work on ff

skins/base/css/molecules/RoomHeader.css

@@ -27,11 +27,10 @@ limitations under the License.
     display: -moz-box;
     display: -ms-flexbox;
     display: -webkit-flex;
-    display: flex;    
+    display: flex;
 }
 
 .mx_RoomHeader_leftRow {
-    display: table-row;
     height: 48px;
 
     -webkit-box-ordinal-group: 1;
@@ -44,7 +43,6 @@ limitations under the License.
 }
 
 .mx_RoomHeader_rightRow {
-    display: table-row;
     height: 48px;
     background-color: #fff;
     border-radius: 48px;
@@ -88,6 +86,7 @@ limitations under the License.
 
 .mx_RoomHeader_avatar {
     display: table-cell;
+    width: 48px;
     height: 50px;
     vertical-align: middle;
 }