abuild: use fetch_uri_mirror when downloading sources

abuild.in

@@ -192,7 +192,7 @@ default_fetch() {
 	mkdir -p "$srcdir"
 	for s in $source; do
 		if is_remote "$s"; then
-			uri_fetch "$s" || return 1
+			uri_fetch_mirror "$s" || return 1
 			ln -sf "$SRCDEST/${s##*/}" "$srcdir"/
 		else		
 			ln -sf "$startdir/$s" "$srcdir/"