*: developer machine HSPKI credentials

In addition to k8s certificates, prodaccess now issues HSPKI
certificates, with DN=$username.sso.hswaw.net. These are installed into
XDG_CONFIG_HOME (or os equiv).

//go/pki will now automatically attempt to load these certificates. This
means you can now run any pki-dependant tool with -hspki_disable, and
with automatic mTLS!

Change-Id: I5b28e193e7c968d621bab0d42aabd6f0510fed6d
diff --git a/cluster/prodvider/proto/BUILD.bazel b/cluster/prodvider/proto/BUILD.bazel
index 2efd457..0817dfb 100644
--- a/cluster/prodvider/proto/BUILD.bazel
+++ b/cluster/prodvider/proto/BUILD.bazel
@@ -1,3 +1,4 @@
+load("@rules_proto//proto:defs.bzl", "proto_library")
 load("@io_bazel_rules_go//go:def.bzl", "go_library")
 load("@io_bazel_rules_go//proto:def.bzl", "go_proto_library")