local.go:ApplyStartupConfigFile function panics instead of returning an error

[Krzysztof Kirsz]

ApplyStartupConfigFile from local.go file currently panics when something goes wrong opening the config file (for instance when we provide an incorrect startup file path). This prevents applications from properly handling errors. It is also not in line with the function signature, which suggests it should return errors when something goes wrong

Current implementation:
https://github.com/freeconf/restconf/blob/master/device/local.go#L112

func (self *Local) ApplyStartupConfigFile(fname string) error {
	cfgRdr, err := os.Open(fname)
	defer cfgRdr.Close()
	if err != nil {
		panic(err)
	}
	return self.ApplyStartupConfig(cfgRdr)
}

[Krzysztof Kirsz]

I've prepared a PR for the issue #53

[Douglas Hubler]

applied, thank you.