Ignore "1" and "0" as thread pool sizes, do not create thread pools and warn user.
Ignore "1" and "0" as thread pool sizes, do not create thread pools and warn user.

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