Make sure that neither cta-taped nor cta-frontend are terminated by OOM

kill. This is quite likely for cta-taped as its static memory buffer
consume a lot of memory.

tapeserver/cta-taped.service

@@ -6,6 +6,7 @@ After=syslog.target network-online.target
 EnvironmentFile=-/etc/sysconfig/cta-taped
 ExecStart=/usr/bin/cta-taped ${CTA_TAPED_OPTIONS}
 LimitCORE=infinity
+OOMScoreAdjust=-1000
 Type=forking
 Restart=no
 

xroot_plugins/cta-frontend.service

@@ -10,6 +10,7 @@ Restart=always
 RestartSec=10
 StartLimitInterval=0
 StartLimitBurst=0
+OOMScoreAdjust=-1000
 LimitCORE=infinity
 LimitNOFILE=65536