use gnutls-dane library

Makefile

+# gnutls must be compiled with DANE support
 NAME=test_dane
 SRC=dane.c
 OBJ=$(SRC:.c=.o)
 
-CFLAGS=$(shell pkg-config gnutls --cflags)
-LDFLAGS=$(shell pkg-config gnutls --libs)
+CFLAGS=$(shell pkg-config gnutls gnutls-dane --cflags)
+LDFLAGS=$(shell pkg-config gnutls gnutls-dane --libs)
 
 all: $(NAME)
 $(NAME): $(OBJ)