remove some unused *_PROTOCOL from export

Things like SERVICE_PROTOCOL and KEYSTONE_AUTH_PROTOCOL shouldn't
really be exported in openrc as they encourage using them directly to
build up keystone urls instead of actually using the OS_AUTH_URL.

Remove them.

Change-Id: I4b7cc680f7f14dae29b706a227be540c9e212cad
diff --git a/functions-common b/functions-common
index 90c9200..56dd203 100644
--- a/functions-common
+++ b/functions-common
@@ -48,8 +48,8 @@
 
 # Save these variables to .stackenv
 STACK_ENV_VARS="BASE_SQL_CONN DATA_DIR DEST ENABLED_SERVICES HOST_IP \
-    KEYSTONE_AUTH_PROTOCOL KEYSTONE_AUTH_URI KEYSTONE_SERVICE_URI \
-    LOGFILE OS_CACERT SERVICE_HOST SERVICE_PROTOCOL STACK_USER TLS_IP \
+    KEYSTONE_AUTH_URI KEYSTONE_SERVICE_URI \
+    LOGFILE OS_CACERT SERVICE_HOST STACK_USER TLS_IP \
     HOST_IPV6 SERVICE_IP_VERSION"