message_view: Update date on sticky header after rendering narrow.

On a fresh render of a narrow if the view doesn't scroll,
`update_sticky_recipient_headers` is not called. So, we need call
it after we have scrolled to the message we want to select.

web/src/message_view.ts

@@ -1129,6 +1129,7 @@ export function render_message_list_with_selected_message(opts: {
         // narrowing
         message_lists.current.view.set_message_offset(select_offset);
     }
+    message_lists.current.view.update_sticky_recipient_headers();
     unread_ops.process_visible();
     narrow_history.save_narrow_state_and_flush();
 }

web/tests/narrow_activate.test.js

@@ -31,6 +31,7 @@ const message_lists = mock_esm("../src/message_lists", {
                 removeClass: noop,
                 addClass: noop,
             },
+            update_sticky_recipient_headers: noop,
         },
         data: {
             filter: new Filter([{operator: "in", operand: "all"}]),
@@ -141,6 +142,7 @@ function stub_message_list() {
                 removeClass: noop,
                 addClass: noop,
             },
+            update_sticky_recipient_headers: noop,
         };
 
         get(msg_id) {