cmd/*, lib/build: Set correct LongVersion (fixes #5993) (#5997)

The relay and discosrv didn't use the new lib/build package, now they
do. Conversely the lib/build package wasn't aware there might be other
users and hard coded the program name - now it's set by the build
script

cmd/strelaysrv/status.go

@@ -10,6 +10,8 @@ import (
 	"runtime"
 	"sync/atomic"
 	"time"
+
+	"github.com/syncthing/syncthing/lib/build"
 )
 
 var rc *rateCalculator
@@ -40,10 +42,10 @@ func getStatus(w http.ResponseWriter, r *http.Request) {
 
 	sessionMut.Lock()
 	// This can potentially be double the number of pending sessions, as each session has two keys, one for each side.
-	status["version"] = Version
-	status["buildHost"] = BuildHost
-	status["buildUser"] = BuildUser
-	status["buildDate"] = BuildDate
+	status["version"] = build.Version
+	status["buildHost"] = build.Host
+	status["buildUser"] = build.User
+	status["buildDate"] = build.Date
 	status["startTime"] = rc.startTime
 	status["uptimeSeconds"] = time.Since(rc.startTime) / time.Second
 	status["numPendingSessionKeys"] = len(pendingSessions)