slapos-node package: fix the standalone build.sh script

FIxup of e8220174fdfc386100a4927400d959c50d1be449
17 jobs for feat/lamp-py3 in 0 seconds
Status Job ID Name Coverage
  External
failed SlapOS.SlapRunner.ResilienceTest-Master

09:20:08

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

05:20:35

failed SlapOS.SlapRunner.ResilienceTest-Master

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

00:02:22

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

00:02:25

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

00:02:20

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

00:02:21

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

00:02:22

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

00:02:21

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

00:02:23

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

00:02:23

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

00:02:23

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

00:02:22

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

00:02:22

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

00:02:23

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

00:02:22

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

00:02:24