Upgrade unbound library

These files were pulled from the 1.6.3 release tarball.

This new version builds against OpenSSL version 1.1 which will be
the default in the new Debian Stable which is due to be released
RealSoonNow (tm).

external/unbound/libunbound/context.c

@@ -62,6 +62,7 @@ context_finalize(struct ub_ctx* ctx)
 	config_apply(cfg);
 	if(!modstack_setup(&ctx->mods, cfg->module_conf, ctx->env))
 		return UB_INITFAIL;
+	log_edns_known_options(VERB_ALGO, ctx->env);
 	ctx->local_zones = local_zones_create();
 	if(!ctx->local_zones)
 		return UB_NOMEM;
@@ -126,7 +127,7 @@ find_id(struct ub_ctx* ctx, int* id)
 
 struct ctx_query* 
 context_new(struct ub_ctx* ctx, const char* name, int rrtype, int rrclass, 
-	ub_callback_t cb, void* cbarg)
+	ub_callback_type cb, void* cbarg)
 {
 	struct ctx_query* q = (struct ctx_query*)calloc(1, sizeof(*q));
 	if(!q) return NULL;