Copr drops sqlite databases and AppStream from repo metadata

Just a heads-up for a wider audience about two upcoming Copr changes. We already have AppStream metadata disabled by default for new projects, but there are many old projects where having this enabled causes problems here and there. So we plan to disable it manually even for old projects: https://lists.fedorahosted.org/archives/list/copr-devel@lists.fedorahoste... The SQLite dababases generated by `createrepo_c --database` consume additional storage, and also computational power on Copr Backend. According to info we have, it is unused by modern DNF stacks, and optional for YUM on EL6+ (DB is generated if not already available). https://lists.fedorahosted.org/archives/list/copr-devel@lists.fedorahoste... If you feel this is the wrong decision, please speak up. Thank you! Pavel