Require OsmoMgw in OsmoBsc and update tests

Since Change-Id Ia2882b7ca31a3219c676986e85045fa08a425d7a, osmo-bsc
uses osmo-mgw and utilizes libosmo-mgcp-client to talk to it.

This commit fixes latest constant failures in voice suite.

Change-Id: I1dadd781a357fce33e7bde55e4bcbdaeb4633359
diff --git a/example/resources.conf b/example/resources.conf
index c4c5e31..697b5c8 100644
--- a/example/resources.conf
+++ b/example/resources.conf
@@ -6,6 +6,7 @@
 - addr: 10.42.42.4
 - addr: 10.42.42.5
 - addr: 10.42.42.6
+- addr: 10.42.42.7
 
 bts:
 - label: sysmoBTS 1002