Print Culprit File when UglifyJS Fails
Print Culprit File when UglifyJS Fails

UglifyJS can fail for good reasons such as:
1. Static checker found bad codes (i.e. unclosed parenthesis)
2. ES6 is used in browser asset JS.

Printing the file name helps with debugging.

niftylettuce/express-cdn,niftylettuce/express-cdn