Scan the parsed VMX file, and gather the biggest index of the network
interfaces there: this way, it is possible to parse all the available
network interfaces, instead of just 4 maximum.
Add the VMX file attached to RHBZ#1560917 as testcase esx-in-the-wild-8.
https://bugzilla.redhat.com/show_bug.cgi?id=1560917
Signed-off-by: Pino Toscano <ptoscano@redhat.com>