[Ada] Explicitly add netdb.h support

Author: Fernando Oleo Blanco

wrapper/Ada/user_settings.h

@@ -37,6 +37,9 @@ extern "C" {
 /* Usually comes from configure -> config.h */
 #define HAVE_SYS_TIME_H
 
+/* Explicitly define NETDB support */
+#define HAVE_NETDB_H
+
 /* Features */
 #define SINGLE_THREADED
 #define WOLFSSL_IGNORE_FILE_WARN /* Ignore *.c include warnings */