Protect: Revert XML RPC request should get hard blocker quicke (#9312)

Since a lot of third party services relied on this be able to connect and were blocked as a result we decided to revert the PR.

If someone want to hadern their XMLRPC connection they can use the following code instead.

```
add_filter( 'jpp_use_captcha_when_blocked', 'jetpack_no_captia_on_xmlrpc_requests' );
function jetpack_no_captia_on_xmlrpc_requests($allow_math_fallback) {
if( Jetpack_Constants::is_true( 'XMLRPC_REQUEST' ) ) {
return false;
}
return $allow_math_fallback;
}
```

modules/protect.php

@@ -554,7 +554,7 @@ function block_with_math() {
 		 * @param bool true Should we fallback to the Math questions when an IP is blocked. Default to true.
 		 */
 		$allow_math_fallback_on_fail = apply_filters( 'jpp_use_captcha_when_blocked', true );
-		if ( ! $allow_math_fallback_on_fail || Jetpack_Constants::is_true( 'XMLRPC_REQUEST' ) ) {
+		if ( ! $allow_math_fallback_on_fail  ) {
 			$this->kill_login();
 		}
 		include_once dirname( __FILE__ ) . '/protect/math-fallback.php';