[packaging] Switch using 3.0 native source format

    Related-Prod: https://mirantis.jira.com/browse/PROD-21900

Change-Id: I8d1a4f930ac103a00125169cf4eea80871ec0ea5
diff --git a/debian/source/format b/debian/source/format
index 163aaf8..89ae9db 100644
--- a/debian/source/format
+++ b/debian/source/format
@@ -1 +1 @@
-3.0 (quilt)
+3.0 (native)