protocol/service: defensive storage.contains check — heartwood

In the case of the storage.contains call returning an error, it would be preferable to log the error and continue checking for missing repositories.

             if !policy.is_allow() {
                 continue;
             }
             if self.storage.contains(&rid)? {
                 continue;
             match self.storage.contains(&rid) {
                 Ok(exists) => {
                     if exists {
                         continue;
                     }
                 }
                 Err(err) => {
                     log::warn!(target: "protocol::filter", "Failed to check if {rid} exists: {err}");
                     continue;
                 }
             }
             match self.seeds(&rid, [self.node_id()].into()) {
                 Ok(seeds) => {