*: add gomod placeholders for generated files

Change-Id: I8a4824ff31590185cd45fd43cc065bb8e2fa7bb2
Reviewed-on: https://gerrit.hackerspace.pl/c/hscloud/+/1580
Reviewed-by: q3k <q3k@hackerspace.pl>
diff --git a/dc/m6220-proxy/proto/gomod-generated-placeholder.go b/dc/m6220-proxy/proto/gomod-generated-placeholder.go
new file mode 100644
index 0000000..92256db
--- /dev/null
+++ b/dc/m6220-proxy/proto/gomod-generated-placeholder.go
@@ -0,0 +1 @@
+package proto