[colord] NULL checksum prevents loading of two different profiles

[Alexey Galakhov]

Hi,

> Hmm, I'm guessing you're not calling
> cd_icc_store_set_load_flags(CD_ICC_LOAD_FLAGS_FALLBACK_MD5)

You're right. Adding this call fixed the issue. Thanks.

> I've pushed this:
> https://github.com/hughsie/colord/commit/c11675831eb38ea13807decf1bc73b1638ba516d
> -- can you please test it and tell me if it fixes the issue? If so,
> I'll push to stable too. Thanks!

It works. But I think hacking flags in set_flags() is quite confusing
since the user expects this value passed to the loader directly. Default
value of flahgs is reasonable, of course.

I suggest making something like CD_ICC_LOAD_FLAGS_NO_FALLBACK_MD5 in one
of the future versions instead.

Regards,
Alex