Default to undef for syncversion parameter in selinux::module
Default to undef for syncversion parameter in selinux::module

Newer SELinux tools don't show the modules version number when
calling `semodule -l`. Unfortunatly there is a bug in puppet's
selmodule type which leads to re-applying the resource every
time even when syncversion is false. Only undef works.

This change defaults the syncversion parameter to undef instead
of true.

This fixes the repeated change:

```
Selmodule[puppet_selinux_test_policy]/syncversion: syncversion changed 'false' to 'true'
```

See also: PUP-6908, PUP-5649

vchepkov/puppet-selinux,jfryman/puppet-selinux,vchepkov/puppet-selinux,vchepkov/puppet-selinux