fix for 'No updates are available to install' error
resolves common problem of false `No updates are available to install` errors after updating FreeBSD base OS files.
```yml
TASK [freebsd-update : Install FreeBSD updates] ****************************************************
fatal: [freebsd6]: FAILED! => {"changed": true, "cmd": ["freebsd-update", "install", "--not-running-from-cron"], "delta": "0:00:00.274477", "end": "2018-05-14 18:13:56.977638", "msg": "non-zero return code", "rc": 1, "start": "2018-05-14 18:13:56.703161", "stderr": "rm: filelist: No such file or directory", "stderr_lines": ["rm: filelist: No such file or directory"], "stdout": "src component not installed, skipped\nInstalling updates...", "stdout_lines": ["src component not installed, skipped", "Installing updates..."]}
changed: [freebsd5]
TASK [freebsd-update : debug] **********************************************************************
```