Resolve plex image issue (maybe?)

image.php

@@ -5,7 +5,7 @@ require_once("user.php");
 $image_url = $_GET['img'];
 $image_height = $_GET['height'];
 $image_width = $_GET['width'];
-$image_source = $_GET['source'];
+$image_source = (isset($_GET['source']) ? isset($_GET['source'] : 'plex');
 
 switch ($image_source) {
 	case 'emby':
@@ -27,6 +27,7 @@ switch ($image_source) {
 			echo "Invalid Emby Request";	
 		}
 		break;
+	case 'plex':
 	default:
 		$urlCheck = stripos(PLEXURL, "http");
 
@@ -46,4 +47,4 @@ switch ($image_source) {
 			echo "Invalid Plex Request";	
 		}
 		break;
-}
+}