Disable call to ::_seterrormode when WINAPI_FAMILY is defined to something other than WINAPI_FAMILY_DESKTOP_APP. Refs #143.

include/boost/core/detail/lwt_unattended.hpp

@@ -35,9 +35,13 @@ inline void lwt_unattended()
 #  pragma clang diagnostic ignored "-Wdeprecated-declarations"
 # endif
 
+#if !defined(WINAPI_FAMILY) || WINAPI_FAMILY == 100 /*WINAPI_FAMILY_DESKTOP_APP*/
+
     // disable message box on crash
     ::_seterrormode( /*SEM_NOGPFAULTERRORBOX*/ 0x0002 );
 
+#endif
+
 # if defined(__clang__)
 #  pragma clang diagnostic pop
 # endif