global management of the default interface
It would be very useful if we can manage from the main configuration the default interface tvheadend will use.
Otherwize, it looks like tvheadend use the first one found, which is in my case not the most relevant one.
- allow to configure a default network interface from configuration > general
- add an option in the muxes interface drop drown list which allow to use the default configuration.
- for the new muxes, use by default the default configuration.