import-debian-package: when "upstream" is set to "unstable", use "sid" instead

For consistency across all Apertis packages.

Signed-off-by: Dylan Aïssi <dylan.aissi@collabora.com>

tools/import-debian-package

@@ -268,6 +268,9 @@ def do_import(args):
         f.write_text("* -text -eol -crlf -ident -filter -working-tree-encoding -export-subst\n")
 
     package, downstream, upstream = args.package, args.downstreams.pop(0), args.upstream
+    if upstream == "unstable":
+        logging.warning('Switching "upstream" to "sid" instead of "unstable" for consistency!')
+        upstream = "sid"
     upstream_release = upstream.split('/')[-1]
     downstream_distro, downstream_release = downstream.split('/', maxsplit=2)