contrib: build-osmo-trx: build new dep libosmocore

Since 8b843e5bed6e3dab1068b86805e557a196f9aa4c, osmo-trx depends on
libosmocore.

Change-Id: I63d09339da5be7af638efe9e07f0c0ed31738ed1
diff --git a/contrib/jenkins-build-osmo-trx.sh b/contrib/jenkins-build-osmo-trx.sh
index b996cfe..194266f 100755
--- a/contrib/jenkins-build-osmo-trx.sh
+++ b/contrib/jenkins-build-osmo-trx.sh
@@ -4,6 +4,7 @@
 name="osmo-trx"
 . "$(dirname "$0")/jenkins-build-common.sh"
 
+build_repo libosmocore --disable-doxygen
 build_repo osmo-trx --without-sse
 
 create_bin_tgz osmo-trx