Debian include for $config_file_per_interface is too restrictive

[cgoubert]

Expected Behavior

When using $config_file_per_interface on Debian, /etc/network/interfaces should source everything in /etc/network/interfaces.d/
This breaks some tools that configure additional interfaces out of puppet control.

Actual Behavior

source is restricted to /etc/network/interfaces.d/*.cfg

Specifications

puppet6, on master branch, debian 10

Proposed fix

Remove ".cfg" from this line

puppet-network/manifests/interface.pp

Line 732 in 9ebd4e4

line => 'source /etc/network/interfaces.d/*.cfg',