[FAB-7405] Fix misleading in Comments

Comment in fabric/gossip/state/state.go Line:706, should be "Select peer to ask for blocks" rather than "Select peers to ask for blocks", since it just selects one peer, so "peers" in this comment will be misleading.

Change-Id: I15a7c66fd9d9ede7cd2dada2eef16656bc04b594
Signed-off-by: c_lq <Caojing@hyperchain.cn>

gossip/state/state.go

@@ -703,7 +703,7 @@ func (s *GossipStateProviderImpl) selectPeerToRequestFrom(height uint64) (*comm.
 		return nil, errors.New("there are no peers to ask for missing blocks from")
 	}
 
-	// Select peers to ask for blocks
+	// Select peer to ask for blocks
 	return peers[util.RandomInt(n)], nil
 }