get cover automaticly from mp3 files
added 'try' to fix broken encoding
LAMBDA-76: get cover only for "audio-only" and save in encoding folder
LAMBDA-76: remove try and use if to check if there is a cover
LAMBDA-76: ignore the cover in the file if there already is a cover
Merge branch 'getcoverauto' into dev
Merge branch 'dev' of github.com:LambdaCast/LambdaCast into dev