remote controller: Fix entrypoint interaction bugs

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>

monitor/monitor.go

@@ -283,6 +283,7 @@ func (m *monitor) startInvoke(ctx context.Context, pid string, cfg controllerapi
 	if len(cfg.Entrypoint) == 0 && len(cfg.Cmd) == 0 {
 		cfg.Entrypoint = []string{"sh"} // launch shell by default
 		cfg.Cmd = []string{}
+		cfg.NoCmd = false
 	}
 	go func() {
 		// Start a new invoke