[skip ci] fix wrapping of participants list

app/assets/stylesheets/pages/issuable.scss

@@ -430,6 +430,7 @@
 
 .participants-list {
   display: flex;
+  flex-wrap: wrap;
   justify-content: space-between;
   margin: -5px;
 }

app/views/shared/issuable/_participants.html.haml

@@ -12,9 +12,9 @@
     - participants.each do |participant|
       .participants-author.js-participants-author
         = link_to_member(@project, participant, name: false, size: 24)
-    - if participants_extra > 0
-      .participants-more
-        %a.js-participants-more{ href: "#", data: { original_text: "+ #{participants_size - 7} more", less_text: "- show less" } }
-          + #{participants_extra} more
+  - if participants_extra > 0
+    .hide-collapsed.participants-more
+      %a.js-participants-more{ href: "#", data: { original_text: "+ #{participants_size - 7} more", less_text: "- show less" } }
+        + #{participants_extra} more
 :javascript
   IssuableContext.prototype.PARTICIPANTS_ROW_COUNT = #{participants_row};