Ignore osmo-ns-dummy

Change-Id: Id562988942be13b83c552bdaa1ad93e275b3d0ae
diff --git a/.gitignore b/.gitignore
index 269ce8a..936773e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -103,3 +103,4 @@
 coverage-cobertura.xml
 
 contrib/libosmocore.spec
+/utils/osmo-ns-dummy