fix(fc_tasks): add missing io/flashfs.h include (#1235)

Closes #1234.

Author: nerdCopter

src/main/fc/fc_tasks.c

@@ -71,6 +71,7 @@
 #include "io/asyncfatfs/asyncfatfs.h"
 #include "io/beeper.h"
 #include "io/dashboard.h"
+#include "io/flashfs.h"
 #include "io/gps.h"
 #include "io/ledstrip.h"
 #include "io/osd.h"