[cern] Add CERN_CHART_ENABLED in write-heat-params
To not install cern-{keytab,hostcert} in worker nodes we need to pass CERN_CHART_ENABLED via heat-params. It was missed in: a19b045d
Change-Id: I7d1dc3150979f0cab9cb909656346848c7a3ac98 Signed-off-by: Spyros Trigazis spyridon.trigazis@cern.ch