bugfix: failed to build on 32bits Linux OS.

bugfix: failed to build on 32bits Linux OS.

bugfix: did't free ngx_regex_match_context.

bugfix: fixed warning.

bugfix: failed to build with openssl 1.x.x and boringssl.

optimize: fixed build warning.

feature: bumped api version to 17.

bumped version of stream-lua-nginx-module to 16.

bugfix: failed to build on windows.

bumped stream-lua-nginx-module to 15.