Whitespace around language stops detection

[ciaranmcnulty]

We do things slightly differently to cucumber, removing this line will cause a failing test

https://github.com/Behat/Gherkin/blob/master/tests/Behat/Gherkin/Cucumber/CompatibilityTest.php#L36

[stof]

We have other issues regarding language IMO. AFAICT, the parser will parse them in other places than at the top of the file (or at least it tries to do it, as it is part of parseExpression)