Ignore failing deletion of swap

[jmeridth]

Description

Due to using hypriot, which doesn't have dphys-swapfile installed by default, the current deletion process fails. Adding ignore_errors fixes this.

Testing

TASK [kubeadm : Disable Swap] **************************************************************************************************************************************************************************************************************************************************
fatal: [rak8s000]: FAILED! => {"changed": true, "cmd": "dphys-swapfile swapoff && dphys-swapfile uninstall && update-rc.d dphys-swapfile remove", "delta": "0:00:00.005302", "end": "2018-12-24 20:35:44.430288", "msg": "non-zero return code", "rc": 127, "start": "2018-12-24 20:35:44.424986", "stderr": "/bin/sh: 1: dphys-swapfile: not found", "stderr_lines": ["/bin/sh: 1: dphys-swapfile: not found"], "stdout": "", "stdout_lines": []}
...ignoring

[chris-short]

Thank you!