Remove duplicate parameters from local.conf example
Remove duplicate parameters from local.conf example

IRONIC_ENABLED_NETWORK_INTERFACES and IRONIC_NETWORK_INTERFACE are
duplicate in local.conf example for multitenant networking.

This patch removes these duplicate parameters.

Closes-Bug: 1611216
Change-Id: I860acf62e4cc62f2bfba44ab908cd8f8edc91f4a

pshchelo/ironic,pshchelo/ironic,NaohiroTamura/ironic,SauloAislan/ironic,SauloAislan/ironic,openstack/ironic,openstack/ironic,NaohiroTamura/ironic