gbproxy: Use separate NS-VC for data / signalling on SGSN side

As we know, many production deployments have SGSN architectures with
clear control / user plane split.  In such situations, IP-SNS of the
SGSN informs us of two (classes of) IP endpoints:

    some that have control_weight > 0 and data_weight 0
    some that have control_weight 0 and data_weight > 0

Let's adjust the GBProxy_Tests.ttcn to use such a configuration for
each of the two simulated SGSNs.

Change-Id: If0e404bdf2c30a5e18748695608611be83f61109
Closes: OS#4953
diff --git a/gbproxy/GBProxy_Tests.ttcn b/gbproxy/GBProxy_Tests.ttcn
index e1d2e59..e3e61f4 100644
--- a/gbproxy/GBProxy_Tests.ttcn
+++ b/gbproxy/GBProxy_Tests.ttcn
@@ -68,11 +68,24 @@
 							local_ip := "127.0.0.10",
 							remote_udp_port := 23000,
 							remote_ip := "127.0.0.1",
-							data_weight := 1,
+							data_weight := 0,
 							signalling_weight := 1
 						}
 					},
 					nsvci := 101
+				}, {
+					provider := {
+						ip := {
+							address_family := AF_INET,
+							local_udp_port := 7770,
+							local_ip := "127.0.0.10",
+							remote_udp_port := 23000,
+							remote_ip := "127.0.0.1",
+							data_weight := 1,
+							signalling_weight := 0
+						}
+					},
+					nsvci := 201
 				}
 
 			}
@@ -89,11 +102,24 @@
 							local_ip := "127.0.0.11",
 							remote_udp_port := 23000,
 							remote_ip := "127.0.0.1",
-							data_weight := 1,
+							data_weight := 0,
 							signalling_weight := 1
 						}
 					},
 					nsvci := 102
+				}, {
+					provider := {
+						ip := {
+							address_family := AF_INET,
+							local_udp_port := 8880,
+							local_ip := "127.0.0.11",
+							remote_udp_port := 23000,
+							remote_ip := "127.0.0.1",
+							data_weight := 1,
+							signalling_weight := 0
+						}
+					},
+					nsvci := 202
 				}
 			}
 		}