chore(community): community itself has admin rights

This might look like a weird requirement at a fist glance.
The reason this is needed, is because some message signals require
admin rights to take effect (e.g. PinMessage).

When messages are imported from third-party services,
translated to status messages, signed by the community, and eventually distributed
via the archive protocol, we need to ensure that messages signed
by the community itself are considered as admin privileges as well,
so they can be correctly replayed into the database.

protocol/communities/community.go

@@ -648,6 +648,10 @@ func (o *Community) hasMemberPermission(member *protobuf.CommunityMember, permis
 }
 
 func (o *Community) hasPermission(pk *ecdsa.PublicKey, roles map[protobuf.CommunityMember_Roles]bool) bool {
+	if common.IsPubKeyEqual(pk, o.config.ID) {
+		return true
+	}
+
 	member := o.getMember(pk)
 	if member == nil {
 		return false