go_spec: fix typo (pointed out by Hiroshi Iwatani)

R=iant
CC=golang-dev
https://golang.org/cl/2128045

doc/go_spec.html

 <!-- title The Go Programming Language Specification -->
-<!-- subtitle Version of Sep 2, 2010 -->
+<!-- subtitle Version of Sep 7, 2010 -->
 
 <!--
 TODO
@@ -591,7 +591,7 @@ for floating-point values, both the mantissa and exponent must be twice as large
 <p>
 A type determines the set of values and operations specific to values of that
 type.  A type may be specified by a (possibly qualified) <i>type name</i>
-(§<a href="#Qualified_identifier">Qualified identifier</a>, §<a href="#Type_declarations">Type declarations</a>) or a <i>type literal</i>,
+(§<a href="#Qualified_identifiers">Qualified identifier</a>, §<a href="#Type_declarations">Type declarations</a>) or a <i>type literal</i>,
 which composes a new type from previously declared types.
 </p>