bsc: Get rid of module param mp_media_mgw_offer_ipv6

This param is not needed anymore sincenew releases used in -latest don't
need to disable it.
Let's keep the possibility to change behavior from within test and leave
v6 enabled by default as it used to be.

Related: OS#5042
Change-Id: Ic693885dd3d4259dc6ce80643d25c7d432148d3d
diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index dc94b74..e4e2d1a 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -671,8 +671,6 @@
 	boolean mp_enable_osmux_test := true;
 	/* Value set in osmo-bsc.cfg "ms max power" */
 	uint8_t mp_exp_ms_power_level := 7;
-
-	boolean mp_media_mgw_offer_ipv6 := true;
 }
 
 private function f_gen_test_hdlr_pars(integer bssap_idx := 0) return TestHdlrParams {
@@ -685,7 +683,6 @@
 	}
 	pars.exp_ms_power_level := mp_exp_ms_power_level;
 	pars.mscpool.bssap_idx := bssap_idx;
-	pars.media_mgw_offer_ipv6 := mp_media_mgw_offer_ipv6;
 
 	return pars;
 }