removed offending line that hid threads view on mobile (#27428)

Automatic Merge

webapp/channels/src/components/threading/global_threads/global_threads.scss

@@ -110,8 +110,6 @@
     }
 
     @media screen and (max-width: 768px) {
-        grid-template-rows: 0 1fr;
-
         > .Header {
             display: none;
         }