Call SetBlockProfileRate even it the profiling port is not set

Signed-off-by: Jean-Noël Moyne <jnmoyne@gmail.com>

server/server.go

@@ -2093,6 +2093,9 @@ func (s *Server) Start() {
 	// Pprof http endpoint for the profiler.
 	if opts.ProfPort != 0 {
 		s.StartProfiler()
+	} else {
+		// Enable blocking profile even if no port defined since profiling is always possible over $SYS requests
+		runtime.SetBlockProfileRate(1)
 	}
 
 	if opts.ConfigFile != _EMPTY_ {