doc/go1.4.html: fix typo

Change-Id: I5bfeeef53665b1ef79ec0e4a6ae0eb4aa3e95603
Signed-off-by: Shenghou Ma <minux@golang.org>
Reviewed-on: https://go-review.googlesource.com/8021Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

doc/go1.4.html

@@ -677,7 +677,7 @@ now supports ALPN as defined in <a href="http://tools.ietf.org/html/rfc7301">RFC
 The <a href="/pkg/crypto/tls/"><code>crypto/tls</code></a> package
 now supports programmatic selection of server certificates
 through the new <a href="/pkg/crypto/tls/#Config.CertificateForName"><code>CertificateForName</code></a> function
-of the <a href="/pkg/crypo/tls/#Config"><code>Config</code></a> struct.
+of the <a href="/pkg/crypto/tls/#Config"><code>Config</code></a> struct.
 </li>
 
 <li>