BTS_Tests: use 0.0 as default for mp_ipa_up_delay

The module parameter mp_ipa_up_delay ads a delay after the ipa bring up.
This is relevant for the tests with real BTS hardware, but it is not
relavent for the regular TTCN3 tests.

Lets set the default to 0.0, since the delay caused problems with
TC_rsl_ms_pwr_ctrl and TC_si_sched_13_2bis_2ter_2quater.

Change-Id: I7663cad5df1ee5a8bcdbbf522881999f1be9f4fe
Related: OS#3960
diff --git a/bts/BTS_Tests.ttcn b/bts/BTS_Tests.ttcn
index 35f51a1..e1c64d6 100644
--- a/bts/BTS_Tests.ttcn
+++ b/bts/BTS_Tests.ttcn
@@ -65,7 +65,7 @@
 	integer mp_timing_offset_256syms_exp := 512;
 	/* Time to wait for RSL conn from BTS during startup of test */
 	float mp_ipa_up_timeout := 15.0;
-	float mp_ipa_up_delay := 3.0;
+	float mp_ipa_up_delay := 0.0;
 }
 
 type record of RslChannelNr ChannelNrs;