p2p: reduce buffering on channels (#6609)

Having smaller buffers in each reactor/channel will mean that there will be fewer stale messages.

internal/blockchain/v0/reactor.go

@@ -33,10 +33,9 @@ var (
 				ID:                  byte(BlockchainChannel),
 				Priority:            5,
 				SendQueueCapacity:   1000,
-				RecvBufferCapacity:  50 * 4096,
+				RecvBufferCapacity:  1024,
 				RecvMessageCapacity: bc.MaxMsgSize,
-
-				MaxSendBytes: 100,
+				MaxSendBytes:        100,
 			},
 		},
 	}

internal/blockchain/v2/reactor.go

@@ -585,7 +585,7 @@ func (r *BlockchainReactor) GetChannels() []*p2p.ChannelDescriptor {
 			ID:                  BlockchainChannel,
 			Priority:            5,
 			SendQueueCapacity:   2000,
-			RecvBufferCapacity:  50 * 4096,
+			RecvBufferCapacity:  1024,
 			RecvMessageCapacity: bc.MaxMsgSize,
 		},
 	}