Remove superflous sling.java.version=6 as it's the default now

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1687505 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/pom.xml b/pom.xml
index a3d0d3a..244ab0b 100644
--- a/pom.xml
+++ b/pom.xml
@@ -47,7 +47,6 @@
   <properties>
     <slf4j.version>1.6.4</slf4j.version>
     <logback.version>1.1.2</logback.version>
-    <sling.java.version>6</sling.java.version>
     <pax-exam.version>3.5.0</pax-exam.version>
 
     <bundle.build.dir>