Add logging to unexpected case in Content\Nav

- Address part of https://github.com/friendica/friendica/issues/8475#issuecomment-653912096

src/Content/Nav.php

@@ -171,6 +171,7 @@ class Nav
 		}
 
 		if (local_user()) {
+			if (!empty($a->user)) {
 				// user menu
 				$nav['usermenu'][] = ['profile/' . $a->user['nickname'], DI::l10n()->t('Status'), '', DI::l10n()->t('Your posts and conversations')];
 				$nav['usermenu'][] = ['profile/' . $a->user['nickname'] . '/profile', DI::l10n()->t('Profile'), '', DI::l10n()->t('Your profile page')];
@@ -185,6 +186,9 @@ class Nav
 					'icon' => (DBA::isResult($contact) ? DI::baseUrl()->remove($contact['micro']) : 'images/person-48.jpg'),
 					'name' => $a->user['username'],
 				];
+			} else {
+				DI::logger()->warning('Empty $a->user for local user'. ['local_user' => local_user(), '$a' => $a]);
+			}
 		}
 
 		// "Home" should also take you home from an authenticated remote profile connection