Patch to make api-checker use Gwt1.6 as its reference Api instead of Gwt1.5

Patch by: amitmanjhi
Review by: rjrjr (desk review) 



git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@5435 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/build.xml b/build.xml
index 77d9860..58cc15e 100755
--- a/build.xml
+++ b/build.xml
@@ -7,7 +7,7 @@
   <property name="target" value="build" />
 
   <property name="gwt.apicheck.config" 
-    location="tools/api-checker/config/gwt15_16userApi.conf"/>
+    location="tools/api-checker/config/gwt16_20userApi.conf"/>
 
   <target name="buildonly" depends="dev, user, servlet, jni" description="Build without docs/samples">
     <gwt.ant dir="distro-source" />