check_manage_home useradd provider needs to add -M on Debian

Regarding the code here:

https://github.com/puppetlabs/puppet/blob/1c77bfb8961587ddf5399cd4a70fc908cac6a6ec/lib/puppet/provider/user/useradd.rb#L127-L135

There is an edge case that is missed. If force_local is true and manage_home is false, then "-M" should be added as a command line argument on Debian Jessie (and possibly others).

If this is not in place, a bug occurs as follows when running on Debian Jessie (and possibly others). First manually create `/home/bob` (like pam_mkhomedir might do) and then try to add `bob` with a resource like this, and it will fail:

user { 'bob':

  force_local => true,

  manage_home => false,

  ... Other Params ...

}