Add an include to get --disable-module-dirauth happy again

src/feature/dircache/dircache.c

@@ -23,6 +23,7 @@
 #include "feature/nodelist/authcert.h"
 #include "feature/nodelist/networkstatus.h"
 #include "feature/nodelist/routerlist.h"
+#include "feature/relay/router.h"
 #include "feature/rend/rendcache.h"
 #include "feature/stats/geoip.h"
 #include "feature/stats/rephist.h"