sm: Fix cert storage for ephemeral certs
* sm/keydb.c (keydb_store_cert): Clear ephemeral flag for existing certs if store should not be ephemeral.
Previously keydb_store_cert would ignore ephemeral certificates
when asked to store a non ephemeral certificate and insert
it again without the flags. This resulted in duplicated
certificates in the keybox.
- GnuPG-bug-id: T1921
- Signed-off-by: Andre Heinecke <aheinecke@intevation.de>