make gsup ipa name configurable in osmo-msc.cfg

Add a 'ipa-name' VTY command which overrides the default IPA name
used by the MSC. This is a prerequisite for inter-MSC handover.

Related: OS#3355
Change-Id: I317d6c59f77e92fbb2b875a83dc0ec2fa5cb6006
diff --git a/tests/msc_vlr/msc_vlr_test_ss.err b/tests/msc_vlr/msc_vlr_test_ss.err
index e0f57aa..fe869ad 100644
--- a/tests/msc_vlr/msc_vlr_test_ss.err
+++ b/tests/msc_vlr/msc_vlr_test_ss.err
@@ -1,5 +1,5 @@
 full talloc report on 'msgb' (total      0 bytes in   1 blocks)
-talloc_total_blocks(tall_bsc_ctx) == 12
+talloc_total_blocks(tall_bsc_ctx) == 13
 
 ===== test_ss_ussd_mo_geran
 - Location Update request causes a GSUP LU request to HLR
@@ -195,7 +195,7 @@
 ===== test_ss_ussd_mo_geran: SUCCESS
 
 full talloc report on 'msgb' (total      0 bytes in   1 blocks)
-talloc_total_blocks(tall_bsc_ctx) == 12
+talloc_total_blocks(tall_bsc_ctx) == 13
 
 ===== test_ss_ussd_no_geran
 - Location Update request causes a GSUP LU request to HLR
@@ -420,8 +420,8 @@
 ===== test_ss_ussd_no_geran: SUCCESS
 
 full talloc report on 'msgb' (total      0 bytes in   1 blocks)
-talloc_total_blocks(tall_bsc_ctx) == 12
+talloc_total_blocks(tall_bsc_ctx) == 13
 
 full talloc report on 'msgb' (total      0 bytes in   1 blocks)
-talloc_total_blocks(tall_bsc_ctx) == 12
+talloc_total_blocks(tall_bsc_ctx) == 13