ESP32: Update esp-idf

cesanta/esp-idf is rebased onto espressif/esp-idf#aece3d6fc62fd91d3c5a87e0ab2ddb5ac51d8ff0

A few wifi changes and VFS support for directory-related functions.

PUBLISHED_FROM=7823db802945122aa1b5453da8abd8e380cbf2fa

mongoose.h

@@ -474,6 +474,7 @@ typedef struct stat cs_stat_t;
 
 #include <assert.h>
 #include <ctype.h>
+#include <dirent.h>
 #include <fcntl.h>
 #include <inttypes.h>
 #include <machine/endian.h>