doc: update 1.6.txt for fmt.Scanf change

Change-Id: Icdce5cdb8676c3bcb73bd943b406000252509521
Reviewed-on: https://go-review.googlesource.com/17174Reviewed-by: Rob Pike <r@golang.org>

doc/go1.6.txt

@@ -25,6 +25,7 @@ bufio: add Scanner.Buffer (https://golang.org/cl/14599/)
 bufio: add ErrFinalToken as a sentinel value for Scan's split functions (https://golang.org/cl/14924)
 crypto/aes: dedicated asm version of AES-GCM (https://golang.org/cl/10484)
 fmt: allow any integer type as an argument to the * operator (https://golang.org/cl/14491/)
+fmt: in Scanf, newlines must match even at end of string (https://golang.org/cl/16165/)
 image: add NYCbCrA types (https://golang.org/cl/15671)
 math/rand: add Read (https://golang.org/cl/14522)
 net/http: HTTP/2.0 support (many CLs)