Changes

ttcn3-gbproxy-test-fr: Fix hdlcnet device names

In Change-Id I80de01c96185c60fe2de7a8ffa9daed2669658e1 we introduced
the wrong hdlcnetX device names.  We must use each devoce only once,
rather than trying to use hdlcnet1..4 twice.

Change-Id: I56f75995fe94b46b0210de2a4f83e384b4e4ca4f