Safe translation of "file missing" in JavaScript

File uploader button is not working when using django in Catalan, because the translation of "file missing" is breaking the Javascript code.

I propose to use this translation escaped. It should not be modified at the translation, as this text appears in another file, in normal html.
Scape translation of file missing

I've followed @yakky recommendations to scape "file missing" (apply escapejs filter without setting a variable for the translation)
Merge pull request #420 from bielfrontera/patch-1

Safe translation of "file missing" in JavaScript