Fix ReflectionType::__toString() is deprecated

As of PHP 7.1.0, ReflectionType::__toString() is deprecated, and ReflectionParameter::getType() may return an instance of ReflectionNamedType. To get the name of the parameter type, ReflectionNamedType() is available in this case.

https://www.php.net/manual/en/reflectionparameter.gettype.php


Signed-off-by: Daniel Kesselberg <mail@danielkesselberg.de>