realm_logo: Rename realm_logo.rerender to realm_logo.render.

As realm_logo.rerender is now used for initial rendering of
logo as well in c8849f8, so we rename this function from
rerender to render.

static/js/ui_init.js

@@ -509,7 +509,7 @@ export function initialize_everything() {
     settings.initialize();
     compose.initialize();
     initialize_navbar();
-    realm_logo.rerender();
+    realm_logo.render();
 
     message_lists.initialize();
     alert_words.initialize(alert_words_params);