The error of compiler:
websocketpp/roles/server.hpp:299: warning: ISO C++ says that these are ambiguous, even though the worst c
onversion for the first is better than the worst conversion for the second:
gcc (GCC) 4.4.6 20110731 (Red Hat 4.4.6-3)
Copyright (C) 2010 Free Software Foundation, Inc.
Correction of compiler error due to ambiguous "call conversionS"