Updating EOS on CI to version 4.8.73

continuousintegration/docker/ctafrontend/cc7/etc/yum/pluginconf.d/versionlock.list

-0:eos-archive-4.8.72-1.el7.cern.x86_64.rpm
-0:eos-cleanup-4.8.72-1.el7.cern.x86_64.rpm
-0:eos-client-4.8.72-1.el7.cern.x86_64.rpm
-0:eos-fuse-4.8.72-1.el7.cern.x86_64.rpm
-0:eos-fuse-core-4.8.72-1.el7.cern.x86_64.rpm
-0:eos-fuse-sysv-4.8.72-1.el7.cern.x86_64.rpm
-0:eos-fusex-4.8.72-1.el7.cern.x86_64.rpm
-0:eos-fusex-core-4.8.72-1.el7.cern.x86_64.rpm
-0:eos-fusex-selinux-4.8.72-1.el7.cern.x86_64.rpm
-0:eos-ns-inspect-4.8.72-1.el7.cern.x86_64.rpm
-0:eos-server-4.8.72-1.el7.cern.x86_64.rpm
-0:eos-srm-4.8.72-1.el7.cern.x86_64.rpm
-0:eos-test-4.8.72-1.el7.cern.x86_64.rpm
-0:eos-testkeytab-4.8.72-1.el7.cern.x86_64.rpm
+0:eos-archive-4.8.73-1.el7.cern.x86_64.rpm
+0:eos-cleanup-4.8.73-1.el7.cern.x86_64.rpm
+0:eos-client-4.8.73-1.el7.cern.x86_64.rpm
+0:eos-fuse-4.8.73-1.el7.cern.x86_64.rpm
+0:eos-fuse-core-4.8.73-1.el7.cern.x86_64.rpm
+0:eos-fuse-sysv-4.8.73-1.el7.cern.x86_64.rpm
+0:eos-fusex-4.8.73-1.el7.cern.x86_64.rpm
+0:eos-fusex-core-4.8.73-1.el7.cern.x86_64.rpm
+0:eos-fusex-selinux-4.8.73-1.el7.cern.x86_64.rpm
+0:eos-ns-inspect-4.8.73-1.el7.cern.x86_64.rpm
+0:eos-server-4.8.73-1.el7.cern.x86_64.rpm
+0:eos-srm-4.8.73-1.el7.cern.x86_64.rpm
+0:eos-test-4.8.73-1.el7.cern.x86_64.rpm
+0:eos-testkeytab-4.8.73-1.el7.cern.x86_64.rpm
 0:eos-xrootd-4.12.8-1.el7.cern.*
 0:eos-xrootd-debuginfo-4.12.8-1.el7.cern.*
 0:eos-folly-2019.11.11.00-1.el7.cern.*