use released version of maven-site-plugin

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@985709 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/pom.xml b/pom.xml
index 0cc50a5..e318cde 100644
--- a/pom.xml
+++ b/pom.xml
@@ -353,7 +353,7 @@
         </file>
       </activation>
       <properties>
-        <sitePluginVersion>3.0-beta-1-SNAPSHOT</sitePluginVersion>
+        <sitePluginVersion>3.0-beta-1</sitePluginVersion>
       </properties>
     </profile>