Call method to hide swipe refresh indicator on UI thread

app/ui/legacy/src/main/java/com/fsck/k9/ui/K9Drawer.kt

@@ -226,9 +226,11 @@ class K9Drawer(private val parent: MessageList, savedInstanceState: Bundle?) : K
                 accountToRefresh, true, true,
                 object : SimpleMessagingListener() {
                     override fun checkMailFinished(context: Context?, account: Account?) {
+                        swipeRefreshLayout.post {
                             swipeRefreshLayout.isRefreshing = false
                         }
                     }
+                }
             )
         }
     }