removed panicing logic in locjson.go

[quenbyako]

panic is awesome for testing, or benchmarking, but not for real logic. it would be so great, if locjson.Load() method returns an error!

[quenbyako]

also, may be it would be a cool idea to processing these errors, bu i don't know how yet (=

[iafan]

This comment needs to be changed accordingly if the code no longer panics

[iafan]

The idea behind using panic was that this kind of error would realistically happen only if the localization file is an invalid JSON file, in which case it's probably best to let the developer known ASAP. I.e. it's more of a development error rather than a runtime error.

Having said that, there's a small chance that loading resource would fail due to a runtime (e.g. I/O) error, and having the method return an error gives flexibility on how to handle this.

See these lines that need to be adjusted as a part of your PR:
https://github.com/iafan/go-l10n/blob/master/examples/desktop/main.go#L15-L17

I recommend creating a wrapper loadJSON() method in this example that will load the localized resource and panic on error (which is fine for the purposes of an example).