NetworkConnection: Ignore duplicate Start() calls.
NetworkConnection: Ignore duplicate Start() calls.

333fred/ntcore,robotdotnet/ntcore,333fred/ntcore,wpilibsuite/ntcore,333fred/ntcore,robotdotnet/ntcore,333fred/ntcore,wpilibsuite/ntcore,wpilibsuite/ntcore,wpilibsuite/ntcore,robotdotnet/ntcore,robotdotnet/ntcore