multi: Update to siphash v1.2.2.

[davecgh]

This modifies the gcs and txscript modules to use the latest siphash v1.2.2.

While here, it also updates the main module to use the latest rpcclient.

• github.com/dchest/siphash@v1.2.2
• github.com/decred/dcrd/rpcclient/v7@v7.0.0-20210129214723-fc227a05904d

[ghost]

Don't know if it's related, starting a new dcrd from branch multi_use_siphash_1_2_2 on rpi4 (ARMv7) with go1.15.7.linux-armv6l.tar.gz (I hope v6 was the right version to use) synced the chain fully, but shows this in the logs for each inbound connection.

2021-01-31 18:15:58.611 [WRN] SYNC: Attempt to lookup unknown peer 78.47.33.192:43014 (inbound)
Stake: goroutine 58 [running]:
runtime/debug.Stack(0x614230, 0x4be6840, 0x2e84a00)
	/home/dev/MAGIC/go/src/runtime/debug/stack.go:24 +0x78
github.com/decred/dcrd/internal/netsync.lookupPeer(0x2e84a00, 0x4be6840, 0x3)
	/home/dev/dcrd/internal/netsync/manager.go:296 +0x44
github.com/decred/dcrd/internal/netsync.(*SyncManager).handleDonePeerMsg(0x2c18240, 0x2e84a00)
	/home/dev/dcrd/internal/netsync/manager.go:577 +0x2c
github.com/decred/dcrd/internal/netsync.(*SyncManager).eventHandler(0x2c18240, 0x8e0970, 0x4be6d60)
	/home/dev/dcrd/internal/netsync/manager.go:1409 +0x7a0
created by github.com/decred/dcrd/internal/netsync.(*SyncManager).Run
	/home/dev/dcrd/internal/netsync/manager.go:1762 +0xa0

[davecgh]

Thanks for the report on that. I'm going to open it up as a separate issue since it's not related to the siphash update.