Adjust priority of network configuration file for debian guests
Adjust priority of network configuration file for debian guests

This adjusts the priority of the network configuration file from 99
to 50 making it easier for customized configuration.

Fixes #9592

chrisroberts/vagrant,mitchellh/vagrant,marxarelli/vagrant,crashlytics/vagrant,sni/vagrant,bryson/vagrant,gitebra/vagrant,bryson/vagrant,marxarelli/vagrant,mitchellh/vagrant,crashlytics/vagrant,sni/vagrant,crashlytics/vagrant,marxarelli/vagrant,sni/vagrant,gitebra/vagrant,chrisroberts/vagrant,chrisroberts/vagrant,chrisroberts/vagrant,crashlytics/vagrant,mitchellh/vagrant,marxarelli/vagrant,mitchellh/vagrant,bryson/vagrant,sni/vagrant,gitebra/vagrant,gitebra/vagrant,bryson/vagrant