[packaging] Switch using 3.0 native source format

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

Change-Id: I6ef96bc3d461be63a3643f6f0fc9982f898f8459
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)