libmicrohttpd: Fix static library
libmicrohttpd: Fix static library

By defining GNUTLS_INTERNAL_BUILD for static build libmicrohttpd.a imports gnutls_malloc without dllimport.
Alexpux/MINGW-packages,stahta01/MINGW-packages,JPeterMugaas/MINGW-packages,oroppas/MINGW-packages,oroppas/MINGW-packages,stahta01/MINGW-packages,oroppas/MINGW-packages,stahta01/MINGW-packages,oscarfv/MINGW-packages,oroppas/MINGW-packages,Alexpux/MINGW-packages,stahta01/MINGW-packages,Alexpux/MINGW-packages,lhmouse/MINGW-packages,oscarfv/MINGW-packages,JPeterMugaas/MINGW-packages,lhmouse/MINGW-packages,oscarfv/MINGW-packages,stahta01/MINGW-packages,JPeterMugaas/MINGW-packages,lhmouse/MINGW-packages,Alexpux/MINGW-packages,lhmouse/MINGW-packages,fabiangreffrath/MINGW-packages,fabiangreffrath/MINGW-packages,Alexpux/MINGW-packages,fabiangreffrath/MINGW-packages,fabiangreffrath/MINGW-packages,oscarfv/MINGW-packages,lhmouse/MINGW-packages,JPeterMugaas/MINGW-packages,oroppas/MINGW-packages,oscarfv/MINGW-packages,stahta01/MINGW-packages,fabiangreffrath/MINGW-packages,JPeterMugaas/MINGW-packages,oscarfv/MINGW-packages,Alexpux/MINGW-packages,JPeterMugaas/MINGW-packages,lhmouse/MINGW-packages,oroppas/MINGW-packages,fabiangreffrath/MINGW-packages