removed css for button

bigbluebutton-html5/imports/ui/components/chat/styles.scss

@@ -12,20 +12,6 @@
   text-decoration: none;
 }
 
-.closeBtn {
-  position: absolute;
-  right: 10px;
-  top: 10px;
-}
-
-// Modifies the close button style
-Button.closeBtn span:first-child {
-  color: $color-gray-light;
-  background: none;
-  border: none;
-  box-shadow: none;
-}
-
 .header {
   margin-top: $lg-padding-x - $sm-padding-x;
   margin-bottom: $lg-padding-x;