Packaging: Remove java-6 directories from debian init script

Closes #6350

src/deb/init.d/elasticsearch

@@ -44,7 +44,7 @@ ES_USER=elasticsearch
 ES_GROUP=elasticsearch
 
 # The first existing directory is used for JAVA_HOME (if JAVA_HOME is not defined in $DEFAULT)
-JDK_DIRS="/usr/lib/jvm/java-7-oracle /usr/lib/jvm/java-7-openjdk /usr/lib/jvm/java-7-openjdk-amd64/ /usr/lib/jvm/java-7-openjdk-armhf /usr/lib/jvm/java-7-openjdk-i386/ /usr/lib/jvm/java-6-sun /usr/lib/jvm/java-6-openjdk /usr/lib/jvm/java-6-openjdk-amd64 /usr/lib/jvm/java-6-openjdk-armhf /usr/lib/jvm/java-6-openjdk-i386 /usr/lib/jvm/default-java"
+JDK_DIRS="/usr/lib/jvm/java-7-oracle /usr/lib/jvm/java-7-openjdk /usr/lib/jvm/java-7-openjdk-amd64/ /usr/lib/jvm/java-7-openjdk-armhf /usr/lib/jvm/java-7-openjdk-i386/ /usr/lib/jvm/default-java"
 
 # Look for the right JVM to use
 for jdir in $JDK_DIRS; do