According to the manpage the rsyncd.conf has a global section without a
module header. Settings for listening port or bind address must be put
there and will not work if defined in a global submodule (i.e. below a
"[global]" header).
This commit changes the ini format generator for the rsyncd service to
allow a global section in the config file without a submodule header.
Fixes#304293
Credits to @nydragon
* remove retrocompat, add incompat release notes
f46be21864