cmd/syncthing: Restore useful levels of traceback on panic

cmd/syncthing/main.go

@@ -23,6 +23,7 @@ import (
 	"path/filepath"
 	"regexp"
 	"runtime"
+	"runtime/debug"
 	"runtime/pprof"
 	"sort"
 	"strconv"
@@ -280,6 +281,9 @@ func parseCommandLineOptions() RuntimeOptions {
 }
 
 func main() {
+	// We want all (our) goroutines in panic traces.
+	debug.SetTraceback("all")
+
 	options := parseCommandLineOptions()
 	l.SetFlags(options.logFlags)