message-location: Fix rounded corners

data/resources/stylesheet/_room_history.scss

@@ -278,7 +278,7 @@ state-group-row.room-history-row {
   }
 }
 
-message-visual-media {
+message-location, message-visual-media {
   border-radius: vendor.$menu_radius;
 
   @include vendor.focus-ring();

src/session/view/content/room_history/message_row/location.rs

@@ -34,6 +34,7 @@ mod imp {
         fn class_init(klass: &mut Self::Class) {
             Self::bind_template(klass);
 
+            klass.set_css_name("message-location");
             klass.set_accessible_role(gtk::AccessibleRole::Group);
         }