doc: mention that reflect.SetMapIndex no longer panics
when deleting from a nil map.  See issue 8051.

LGTM=r
R=golang-codereviews, r, khr
CC=golang-codereviews
https://golang.org/cl/96540051
diff --git a/doc/go1.3.html b/doc/go1.3.html
index d98cdf6..9a9f9f8 100644
--- a/doc/go1.3.html
+++ b/doc/go1.3.html
@@ -510,6 +510,12 @@
 </li>
 
 <li>
+The <a href="/pkg/reflect/#Value.SetMapIndex"><code>SetMapIndex</code></a>
+function in the <a href="/pkg/reflect/"><code>reflect</code></a> package
+no longer panics when deleting from a <code>nil</code> map.
+</li>
+
+<li>
 If the main goroutine calls 
 <a href="/pkg/runtime/#Goexit"><code>runtime.Goexit</code></a>
 and all other goroutines finish execution, the program now always crashes,