lvg module bugfix on vg_options patch

When no vg_options are passed to the module, 'vg_options' still exists
in the module.params dict with a value of None, so the default empty string in
the get method is never used. None cannot be "splitted", which backtraced.
Merge branch 'lvg_fix' of https://github.com/sergevanginderachter/ansible into sergevanginderachter-lvg_fix
Merge branch 'sergevanginderachter-lvg_fix' into devel