cfgutils: Add fixup_free functions to (u)sleep functions

(cherry picked from commit 194d1bd1d1b86a92ee51bb32d88c105eb6130910)

src/modules/cfgutils/cfgutils.c

@@ -134,9 +134,9 @@ static cmd_export_t cmds[]={
 		ANY_ROUTE},
 	{"rand_event",      (cmd_function)rand_event, 0, 0, 0,
 		ANY_ROUTE},
-	{"sleep",  (cmd_function)m_sleep,  1, fixup_igp_null, 0,
+	{"sleep",  (cmd_function)m_sleep,  1, fixup_igp_null, fixup_free_igp_null,
 		ANY_ROUTE},
-	{"usleep", (cmd_function)m_usleep, 1, fixup_igp_null, 0,
+	{"usleep", (cmd_function)m_usleep, 1, fixup_igp_null, fixup_free_igp_null,
 		ANY_ROUTE},
 	{"abort",      (cmd_function)dbg_abort,        0, 0, 0,
 		ANY_ROUTE},