OF-510: Ant buildfile dependency check should allow Java 1.7

git-svn-id: http://svn.igniterealtime.org/svn/repos/openfire/trunk@12948 b35dd754-fafc-0310-a699-88a17e54d16e

build/build.xml

@@ -234,6 +234,7 @@
                 <or>
                     <contains string="${ant.java.version}" substring="1.5"/>
                     <contains string="${ant.java.version}" substring="1.6"/>
+                    <contains string="${ant.java.version}" substring="1.7"/>
                 </or>
             </not>
         </condition>