Update URL of JS SDK in SipCall sample

Author: aiham

sample/SipCall/templates/index.php

@@ -6,7 +6,7 @@
     <link rel='stylesheet' href='/stylesheets/style.css' />
     <link rel='stylesheet' href='/stylesheets/pattern.css' />
     <script src="https://code.jquery.com/jquery-3.1.0.min.js"></script>
-    <script src="https://static.opentok.com/v2/js/opentok.js"></script>
+    <script src="https://static.opentok.com/v2/js/opentok.min.js"></script>
     <script>
       var sessionId = "<?php echo $sessionId ?>";
       var token = "<?php echo $token ?>";