Merge branch 'Bugfix/close_nonblocking_tcp_crash_for_4.0' into 'release/v4.0'

Bugfix/close nonblocking tcp crash for 4.0

See merge request espressif/esp-idf!6517
This commit is contained in:
Jiang Jiang Jian
2019-11-01 11:24:13 +08:00