contrib: Disable dahdi support in libosmo-abis

Since libosmo-abis d4be696bbc20522a0284b6d0aefa872585f6926f it is
enabled by default. Since we don't need it so far and required
dependencies are not available in sysmobts SDK, let's disable it
explicitly.

Change-Id: Id017f3d2f51d30fa53881b627460fb568f19713b
diff --git a/contrib/jenkins-build-osmo-nitb.sh b/contrib/jenkins-build-osmo-nitb.sh
index 4f81fa8..8ecbdba 100755
--- a/contrib/jenkins-build-osmo-nitb.sh
+++ b/contrib/jenkins-build-osmo-nitb.sh
@@ -5,7 +5,7 @@
 . "$(dirname "$0")/jenkins-build-common.sh"
 
 build_repo libosmocore --disable-doxygen
-build_repo libosmo-abis
+build_repo libosmo-abis --disable-dahdi
 build_repo libosmo-netif --disable-doxygen
 build_repo openggsn
 build_repo libsmpp34