cmd/syncthing: Only SetTraceback on Go 1.7+ (fixes #3664)

cmd/syncthing/traceback.go

@@ -0,0 +1,17 @@
+// Copyright (C) 2016 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at http://mozilla.org/MPL/2.0/.
+
+//+build go1.7
+
+package main
+
+import "runtime/debug"
+
+func init() {
+	// We want all (our) goroutines in panic traces.
+	debug.SetTraceback("all")
+}
+