osmocom-nitb debian package improvements.

* Don't enable MNCC sock by default.
* Create important directories.
* Fix init script 'stop' command.
diff --git a/openbsc/debian/osmocom-nitb.dirs b/openbsc/debian/osmocom-nitb.dirs
new file mode 100644
index 0000000..efbca2b
--- /dev/null
+++ b/openbsc/debian/osmocom-nitb.dirs
@@ -0,0 +1,3 @@
+/etc/osmocom
+/var/log/osmocom
+/var/lib/osmocom