Merge branch 'bugfix/scan_fail_when_no_ap_found_v3.2' into 'release/v3.2'

fix the bug when scan fail after STA failed to connect to a nonexistent AP (backport v3.2)

See merge request idf/esp-idf!4913
This commit is contained in:
Jiang Jiang Jian
2019-05-06 11:39:31 +08:00