fix command line option vs data file

I think command line options should have higher priority then settings stored in data file.
For example I have two movies in one folder `Movie1.mkv` and `Movie2.mkv`. I have run utility for first movie passing imdb movie id
```
apple-tv-converter --id 12345 Movie1.mkv
```
And then I run utilty for second movie
```
apple-tv-converter --id 54321 Movie2.mkv
```
But after transcoding for second movie I will have metadata from first movie because id for this movie was written to settings file and was used for transcoding second movie.