stream_filter/httplive.c: IV is supported in version 2 or higher

IV attribute of tag #EXT-X-KEY was parsed for any version of the protocol.
However chapter "7. Protocol version compatibility" lists the IV tag being
protocol version 2 or higher. This patch restricts the IV attribute to version
2 or higher of the protocol.
(cherry picked from commit a07189f8)

modules/stream_filter/httplive.c

@@ -468,14 +468,22 @@ static void parse_Key(stream_t *s, hls_stream_t *hls, char *p_read)
     else if (strncasecmp(attr, "NONE", 4) == 0)
     {
         char *uri = parse_Attributes(p_read, "URI");
-        char *iv = parse_Attributes(p_read, "IV");
-        if ((iv != NULL) || (uri != NULL))
+        if (uri != NULL)
         {
-            msg_Err(s, "#EXT-X-KEY: URI and IV not expected");
+            msg_Err(s, "#EXT-X-KEY: URI not expected");
             p_sys->b_error = true;
-
+        }
+        free(uri);
+        /* IV is only supported in version 2 and above */
+        if (hls->version >= 2)
+        {
+            char *iv = parse_Attributes(p_read, "IV");
+            if (iv != NULL)
+            {
+                msg_Err(s, "#EXT-X-KEY: IV not expected");
+                p_sys->b_error = true;
+            }
             free(iv);
-            free(uri);
         }
     }
     else