BTS_Tests: extend TC_early_immediate_assignment: run on trx_nr=1

This patch demonstrates the problem with handling of the Early IA:

* the first part remains unchanged: assign a channel on C0 (arfcn=871);
* the second (new) part tests channel assignment on C1 (arfcn=873).

As of now, osmo-bts does not meet our expectations for the second part.

Change-Id: I7517574a8095ddfa05c34c4c3d4accf2bd07894b
Related: SYS#6655
1 file changed