added file_exists

--- /Users/ronak/Desktop/murena/nextcloud/ecloud_dev_example/volumes/nextcloud/html/lib/private/NavigationManager.php	2024-01-18 23:59:45

+++ /Users/ronak/Desktop/murena/nextcloud/ecloud_dev_example/volumes/nextcloud/html/lib/private/NavigationManager-new.php	2024-01-19 00:13:16

@@ -318,10 +318,12 @@

 				$order = isset($nav['order']) ? $nav['order'] : 100;

 				$type = $nav['type'];

 				$route = !empty($nav['route']) ? $this->urlGenerator->linkToRoute($nav['route']) : '';

-				$icon = isset($nav['icon']) ? $nav['icon'] : 'app.svg';

+				$icon = isset($nav['icon']) ? $nav['icon'] : '';

+++ /Users/ronak/Desktop/murena/nextcloud/ecloud_dev_example/volumes/nextcloud/html/lib/private/NavigationManager-new.php	2024-01-19 01:03:23

@@ -321,7 +321,10 @@

 				$icon = isset($nav['icon']) ? $nav['icon'] : 'app.svg';

 				foreach ([$icon, "$app.svg"] as $i) {

 					try {

-						$icon = $this->urlGenerator->imagePath($app, $i);

+						if($icon !== ''){

+						$appPath = $this->appManager->getAppPath($app);

+						if (file_exists($appPath . '/img/' . $i)) {

+							$icon = $this->urlGenerator->imagePath($app, $i);

+						}

 						break;