ttcn3-asterisk: Fix ICSI value encoding

As seen in TS 24.229 7.2A.8.2 example.

Change-Id: I02b3d54003bb02e999b27b533a651299dbb53503
---
M ttcn3-asterisk-ims-ue-test/asterisk/pjsip.conf
1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/ttcn3-asterisk-ims-ue-test/asterisk/pjsip.conf b/ttcn3-asterisk-ims-ue-test/asterisk/pjsip.conf
index 8dc4e6c..ac08fe2 100644
--- a/ttcn3-asterisk-ims-ue-test/asterisk/pjsip.conf
+++ b/ttcn3-asterisk-ims-ue-test/asterisk/pjsip.conf
@@ -94,7 +94,7 @@
 expiration=600000
 ims_aka=yes
 contact_user=volte_ims
-contact_header_params=+g.3gpp.icsi-ref="urn\%3Aurn-7\%3A3gpp-service.ims.icsi.mmtel"\;audio\;+sip.instance="<urn:gsma:imei:35876110-027790-0>"
+contact_header_params=+g.3gpp.icsi-ref="urn%3Aurn-7%3A3gpp-service.ims.icsi.mmtel"\;audio\;+sip.instance="<urn:gsma:imei:35876110-027790-0>"
 endpoint=volte_ims
 line=yes
 manual_register=yes

