bsc: f_ipa_unknown_unit_id: use different id

Change the unit_id value, that is supposed to be unknown at BTS, from
0/0/0 to 99/0/0 to make TC_oml_unknown_unit_id pass again. The test was
failing, because a new bts that matches 0/0/0 was added to osmo-bsc.cfg
in [1], [2] and [3].

[1] Ia4ba0e75abd3d45a3422b2525e5f938cdc5a04cc
[2] I1c57a04747f5ec004ccf4657954dcb0b003c24fc (docker-playground)
[3] I00547dccf8908d46df4730cb513fe577956d7683 (docker-playground)

Related: OS#4156
Change-Id: I585ff825c7b6bca17e5c6fb6d670a649965a1653
diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index 2bc1c62..e25bf7f 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -1670,7 +1670,7 @@
 	bts[0].rsl.vc_IPA := IPA_Emulation_CT.create(bts[0].rsl.id & "-IPA");
 	bts[0].rsl.ccm_pars := c_IPA_default_ccm_pars;
 	bts[0].rsl.ccm_pars.name := "Osmocom TTCN-3 BTS Simulator";
-	bts[0].rsl.ccm_pars.unit_id := "0/0/0"; /* value which is unknown at BTS */
+	bts[0].rsl.ccm_pars.unit_id := "99/0/0"; /* value which is unknown at BTS */
 
 	f_ipa_ctrl_start(mp_bsc_ip, mp_bsc_ctrl_port);