Fix typo in agent mac fallback selection

Fix typo in agent mac fallback when no interface is inside the network
 that also contains the api address

Resolves-bug: #1270963

Change-Id: I7744c9fae3db2df63c8e73b0e557a7ff992efe0e
Add fallback test in __check_interfaces_correctness

In some cases, it may be OK for there to be an admin interface
 that is outside the admin network. To support this case we we will
 test if the interface mac matches the mac that contacted us, if this
 is the case, we will use this interface.

This prevents the NetworkManager from erroneously removing interfaces
 from an otherwise valid node.

Resolves-bug: #1271043

Change-Id: I04120d538e2efba6cb7a04cfbd7cb4852f2576c9
bug/1271377 change NetworkGroup.name to String(50)

Change-Id: Iec333c70a799b1be945bd0f212f0a82c0f779222