fix: Fix avatar images

Signed-off-by: Christopher Ng <chrng8@gmail.com>

lib/private/Avatar/AvatarManager.php

@@ -101,6 +101,9 @@ class AvatarManager implements IAvatarManager {
 
 	/**
 	 * return a user specific instance of \OCP\IAvatar
+	 *
+	 * If the user is disabled a guest avatar will be returned
+	 *
 	 * @see \OCP\IAvatar
 	 * @param string $userId the ownCloud user id
 	 * @return \OCP\IAvatar
@@ -113,6 +116,10 @@ class AvatarManager implements IAvatarManager {
 			throw new \Exception('user does not exist');
 		}
 
+		if (!$user->isEnabled()) {
+			return $this->getGuestAvatar($userId);
+		}
+
 		// sanitize userID - fixes casing issue (needed for the filesystem stuff that is done below)
 		$userId = $user->getUID();