Use a dedicated UID/GID for unprivileged execution.

Bug: 23651876
Change-Id: Ie924bbe5cee74e3095876d6386a6ea21399b8d97
diff --git a/config.h b/config.h
index 5dcfad6..3347985 100644
--- a/config.h
+++ b/config.h
@@ -244,12 +244,11 @@
 /* Vendor of Target System */
 /* #undef TARGET_VENDOR */
 
-/* TODO(b/23651876) Reserve proper unprivileged uid/gid for the helper. */
 /* Unprivileged group */
-#define UNPRIV_GROUP "nobody"
+#define UNPRIV_GROUP "tlsdate"
 
 /* Unprivileged user */
-#define UNPRIV_USER "nobody"
+#define UNPRIV_USER "tlsdate"
 
 /* if PolarSSL is enabled */
 /* #undef USE_POLARSSL */