fix a spurious include

src/server/ua_server_internal.h

@@ -9,10 +9,6 @@
 #include "ua_securechannel_manager.h"
 #include "ua_nodestore.h"
 
-#ifdef UA_ENABLE_SUBSCRIPTIONS
-#include "ua_subscription_manager.h"
-#endif
-
 #define ANONYMOUS_POLICY "open62541-anonymous-policy"
 #define USERNAME_POLICY "open62541-username-policy"