Fix mod_auth_gssapi config file location

diff --git a/mod_auth_gssapi b/mod_auth_gssapi
index 7d31b76..538b6b9 160000 (submodule)
--- a/mod_auth_gssapi
+++ b/mod_auth_gssapi
@@ -1 +1 @@
-Subproject commit 7d31b765435d5d5a2f29da262c6805baf10ab0bc
+Subproject commit 538b6b9a2ed40f61dfa218c23ca819e4b98ce102