Hello!

In version 1.34 creating a `Parser` object without explicitly setting the `mTitle` value was deprecated. But as it is just a deprecation yet, there are still cases where `mTitle` can be `null` (it seems like this is even the case when calling the proper service with `MediaWikiServices::getInstance()->getParser()`).

Unfortunately the `Parser::getTitle` method got changed, in a way that it _must_ return an instance of `Title`. No `null` allowed. This leads to a `TypeError`.

I have found two Phabricator tasks, each with a proper patch for this:

- https://phabricator.wikimedia.org/T228881 / https://gerrit.wikimedia.org/r/#/c/mediawiki/core/+/533559/ - https://phabricator.wikimedia.org/T245129 / https://gerrit.wikimedia.org/r/#/c/mediawiki/core/+/571940/

It looks like a very small change. I'd very much appreciate if somebody could review and merge one of these.