fix deprecated

Author: lohanidamodar

example.php

@@ -41,7 +41,7 @@ function getSSLPage($url) {
     // $platform = 'console';
     // $platform = 'server';
 
-    $spec = getSSLPage("https://raw.githubusercontent.com/appwrite/appwrite/master/app/config/specs/swagger2-latest-${platform}.json");
+    $spec = getSSLPage("https://raw.githubusercontent.com/appwrite/appwrite/master/app/config/specs/swagger2-latest-{$platform}.json");
 
     if(empty($spec)) {
         throw new Exception('Failed to fetch spec from Appwrite server');