Fix LibeventConfig.cmake in case of no OpenSSL Previously it fails with, due to empty OPENSSL_FOUND: CMake Error at /home/runner/work/libevent/libevent/build/LibeventConfig.cmake:64 (if): if given arguments: "3.30.3" "VERSION_LESS" "3.15.0" "AND" "1" "AND" "AND" "TRUE" Unknown arguments specified