fix(gallery-service): Preserve ref config

[tvsbrent]

• When updating the configuration of an existing gallery ref, use the existing configuration as the basis instead of the service's default config.

This addresses issue #592

[MurhafSousli]

In this case, we can just use galleryRef.setConfig(config) because it already merges the new config with the existing ones

[tvsbrent]

In this case, we can just use galleryRef.setConfig(config) because it already merges the new config with the existing ones

Could you explain how that might work? I spun up a new StackBlitz - linked below - which calls that method in the ngOnInit, but I didn't see the config changes reflected. Only setting the GALLERY_CONFIG in the provider seemed to have the desired effect:

https://stackblitz.com/edit/ngx-gallery-1iqhwc?file=src%2Fmain.ts

[MurhafSousli]

@tvsbrent I meant in your PR, in the source code change you submitted galleryRef.setConfig(config) should be sufficient