godoc: remove "need more packages?" link

Its need will be addressed in another way by the redesign.

Fixes #2719.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5536062

lib/godoc/package.html

@@ -131,11 +131,6 @@
 	</p>
 {{end}}
 {{with .Dirs}}
-	<p class="detail">
-	Need more packages? The
-	<a href="http://godashboard.appspot.com/package">Package Dashboard</a>
-	provides a list of <a href="/cmd/goinstall/">goinstallable</a> packages.
-	</p>
 	{{/* DirList entries are numbers and strings - no need for FSet */}}
 	<h2 id="Subdirectories">Subdirectories</h2>
 	<p>