main.c: fix compile warning

(cherry picked from commit e4f18cb322d54035fb6825df3a2f712ed03a71db)

main.c

@@ -191,6 +191,7 @@
 #include "ppcfg.h"
 #include "sock_ut.h"
 #include "async_task.h"
+#include "dset.h"
 
 #ifdef DEBUG_DMALLOC
 #include <dmalloc.h>