Update epics gateway name

roles/epics/templates/DOTepics

 # export EPICS base path and configuration to interact with KARA's IOCs
 export LD_LIBRARY_PATH=/usr/local/share/base-{{epics_version}}/lib/linux-x86_64:$LD_LIBRARY_PATH
-export EPICS_CA_ADDR_LIST=$(dig +short ankasr-appcache.anka.kit.edu)
+export EPICS_CA_ADDR_LIST=$(dig +short ankasr-cagw.anka.kit.edu)
 export PATH=/usr/local/share/base-{{epics_version}}/bin/linux-x86_64:$PATH
 export EPICS_BASE=/usr/local/share/base-{{epics_version}}
 export EPICS_HOST_ARCH=linux-x86_64