Before we would just call verify() and only return valid connections
without attempting to fix them.

It is better to use normalize(), because that function is especially there to
accept and repair deprecated configurations that would no longer verify().

This changes behavior in the way that the function now accepts connections
that would have been rejected before.

Since commit b88715e0 normalize() also
adds a missing UUID. Hence this also affects the DBUS method 'AddConnection'
in that it now accepts connections without UUID. Previously, clients were
required to set a UUID for the new connection, now NM core can create a random
one if no UUID is set.

https://bugzilla.gnome.org/show_bug.cgi?id=740813