Improved thread-safe for MHD_set_connection_option()
Improved thread-safe for MHD_set_connection_option()

maru/libmicrohttpd-http2,maru/libmicrohttpd-http2,ghaderer/libmicrohttpd,maru/libmicrohttpd-http2,ghaderer/libmicrohttpd,ghaderer/libmicrohttpd