tailcfg: bump capVer for Noise
// 25: 2021-11-01: MapResponse.Debug.Exit
// 26: 2022-01-12: (nothing, just bumping for 1.20.0)
// 27: 2022-02-18: start of SSHPolicy being respected
-const CurrentCapabilityVersion CapabilityVersion = 27
+// 28: 2022-03-09: client can communicate over Noise.
+const CurrentCapabilityVersion CapabilityVersion = 28
type StableID string
