- Use the correct signature file for source verification
- Rename postfix-3.5.6.tar.gz.sig to postfix-3.5.6.tar.gz.asc (to
prevent confusion, as the signature file from upstream with .sig
extension is incompatible with the build service)
Upstream provides serveral signatures for source verification.
Unfortunately, the one we need uses '.gpg2' as an extension,
so we need to rename this to an extension that is recognized
by the build service. This is handled automatically by the
.spec file when running (locally) 'osc service runall'.
Upstream also provides a signature with '.sig' extension, but
this is for an obsolete PGP format, which is not recognized
by the build service.
OBS-URL: https://build.opensuse.org/request/show/825043
OBS-URL: https://build.opensuse.org/package/show/server:mail/postfix?expand=0&rev=381
