Update download link to 2.6 release (master)
Update download link to 2.6 release (master)

Change build.xml file to use the 2.6 release link for downloads of
add-ons.

veggiespam/zap-extensions,zapbot/zap-extensions,kingthorin/zap-extensions,zaproxy/zap-extensions,thc202/zap-extensions,zaproxy/zap-extensions,rnehra01/zap-extensions,denniskniep/zap-extensions,veggiespam/zap-extensions,psiinon/zap-extensions,denniskniep/zap-extensions,zaproxy/zap-extensions,secdec/zap-extensions,thc202/zap-extensions,secdec/zap-extensions,zapbot/zap-extensions,psiinon/zap-extensions,zaproxy/zap-extensions,rnehra01/zap-extensions,veggiespam/zap-extensions,thc202/zap-extensions,veggiespam/zap-extensions,thc202/zap-extensions,rnehra01/zap-extensions,secdec/zap-extensions,psiinon/zap-extensions,rnehra01/zap-extensions,secdec/zap-extensions,kingthorin/zap-extensions,denniskniep/zap-extensions,JordanGS/zap-extensions,secdec/zap-extensions,rnehra01/zap-extensions,thc202/zap-extensions,veggiespam/zap-extensions,zapbot/zap-extensions,kingthorin/zap-extensions,rnehra01/zap-extensions,JordanGS/zap-extensions,secdec/zap-extensions,veggiespam/zap-extensions,JordanGS/zap-extensions,zapbot/zap-extensions,JordanGS/zap-extensions,zapbot/zap-extensions,psiinon/zap-extensions,psiinon/zap-extensions,JordanGS/zap-extensions,JordanGS/zap-extensions,kingthorin/zap-extensions,kingthorin/zap-extensions,denniskniep/zap-extensions,secdec/zap-extensions,JordanGS/zap-extensions,psiinon/zap-extensions,zaproxy/zap-extensions,denniskniep/zap-extensions,rnehra01/zap-extensions,zapbot/zap-extensions,zaproxy/zap-extensions,kingthorin/zap-extensions,thc202/zap-extensions,denniskniep/zap-extensions