Make TS2 main instances have klystron information

llrfsystem/iocsh/ts2-main.iocsh

 # Snippet TS2 - 1st digitizer
 # This snippet will generate a PV to control which of the digitizers is the main
 
+epicsEnvSet("KLYDB", "")
+
 iocshLoad("$(llrfsystem_DIR)/base.iocsh")
 iocshLoad("$(sis8300llrf_DIR)/sis8300llrf-1-boards.iocsh", "LPSEN=$(LPSEN=1)")