fix invalid filename

[zaggino]

mentioned here #11569

(passes on windows due to fs being case insensitive)

file here: https://github.com/adobe/brackets/blob/master/test/spec/CodeHint-test-files/testRegExp.js

cc @marcelgerber @ficristo

[marcelgerber]

What's weird is that these tests passed before with this exact same invalid filename in place, but merging anyway :)

[ficristo]

This doesn't fix the tests in Extensions \ JavaScript Code Hinting for me.
But it is a good cleanup anyway.

[marcelgerber]

Tests still fail for me, too (Linux). @ficristo Do you also get the message timeout: timed out after 1000 msec waiting for success [undefined]?

[ficristo]

Yes.