cmake LWS_HAVE_SOCKET examples

warmcat/libwebsockets CMakeLists.txt :648 

CHECK_FUNCTION_EXISTS(socket LWS_HAVE_SOCKET)

c-jimenez/open-ocpp 3rdparty/libwebsockets/CMakeLists.txt :572 

CHECK_FUNCTION_EXISTS(socket LWS_HAVE_SOCKET)

fluffos/fluffos src/thirdparty/libwebsockets/CMakeLists.txt :555 

CHECK_FUNCTION_EXISTS(socket LWS_HAVE_SOCKET)