message: Fix build when CAF_LOG_LEVEL is not #defined
diff: @@ -312,6 +312,10 @@ bool operator==(const logger::field& x, const logger::field& y);
  #define CAF_PRETTY_FUN __PRETTY_FUNCTION__
  #endif // CAF_MSVC
  +#ifndef CAF_LOG_COMPONENT
  +#define CAF_LOG_COMPONENT "caf"
  +#endif // CAF_LOG_COMPONENT
  +
  #ifndef CAF_LOG_LEVEL
  #define CAF_LOG_IMPL(unused1, unused2, unused3)
  @@ -331,10 +335,6 @@ inline caf::actor_id caf_set_aid_dummy() { return 0; }
  #else // CAF_LOG_LEVEL
  -#ifndef CAF_LOG_COMPONENT
  -#define CAF_LOG_COMPONENT "caf"
  -#endif // CAF_LOG_COMPONENT
  -
  #define CAF_LOG_IMPL(component, loglvl, message) \
  do { \
  auto CAF_UNIFYN(caf_logger) = caf::logger::current_logger(); \
  