statemachine: remove obsolete comment
statemachine: remove obsolete comment

hashicorp/raft calls Restore() during initialization only, never during
runtime, see the following comment for reference:
https://github.com/hashicorp/raft/blob/5fdd8ee3c3b2cc508e29991c4caf117977034eb1/raft.go#L1863

robustirc/robustirc,robustirc/robustirc,robustirc/robustirc