message: [doc] Improve comment about protected peers
  The comment currently suggests a long-standing node would infrequently protect
  peers under normal circumstances. Clarify that we also protect peers that are
  synced to the same work as our chain tip.
diff: @@ -566,7 +566,7 @@ struct CNodeState {
  * - its connection type is IsBlockOnlyConn() == false
  * - it gave us a valid connecting header
  * - we haven't reached MAX_OUTBOUND_PEERS_TO_PROTECT_FROM_DISCONNECT yet
  - * - it has a better chain than we have
  + * - its chain tip has at least as much work as ours
  *
  * CHAIN_SYNC_TIMEOUT: if a peer's best known block has less work than our tip,
  * set a timeout CHAIN_SYNC_TIMEOUT seconds in the future:
  