[ci] Upgrades to eos version 4.5.6

This version contains several fixes required by the migration tools:
- fixes bug where quota bit was set when directory permissions have
  "executable by all" bit set
- inheritance of extended attributes
- better reporting of errors in case of failure

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

-0:eos-archive-4.5.3-20190730172748gitea30da3.el7.cern.x86_64
-0:eos-cleanup-4.5.3-20190730172748gitea30da3.el7.cern.x86_64
-0:eos-client-4.5.3-20190730172748gitea30da3.el7.cern.x86_64
-0:eos-debuginfo-4.5.3-20190730172748gitea30da3.el7.cern.x86_64
-0:eos-fuse-4.5.3-20190730172748gitea30da3.el7.cern.x86_64
-0:eos-fuse-core-4.5.3-20190730172748gitea30da3.el7.cern.x86_64
-0:eos-fuse-sysv-4.5.3-20190730172748gitea30da3.el7.cern.x86_64
-0:eos-fusex-4.5.3-20190730172748gitea30da3.el7.cern.x86_64
-0:eos-fusex-core-4.5.3-20190730172748gitea30da3.el7.cern.x86_64
-0:eos-fusex-selinux-4.5.3-20190730172748gitea30da3.el7.cern.x86_64
-0:eos-server-4.5.3-20190730172748gitea30da3.el7.cern.x86_64
-0:eos-srm-4.5.3-20190730172748gitea30da3.el7.cern.x86_64
-0:eos-test-4.5.3-20190730172748gitea30da3.el7.cern.x86_64
-0:eos-testkeytab-4.5.3-20190730172748gitea30da3.el7.cern.x86_64
+0:eos-archive-4.5.6-20190829163023gite72c345.el7.cern.x86_64
+0:eos-cleanup-4.5.6-20190829163023gite72c345.el7.cern.x86_64
+0:eos-client-4.5.6-20190829163023gite72c345.el7.cern.x86_64
+0:eos-debuginfo-4.5.6-20190829163023gite72c345.el7.cern.x86_64
+0:eos-fuse-4.5.6-20190829163023gite72c345.el7.cern.x86_64
+0:eos-fuse-core-4.5.6-20190829163023gite72c345.el7.cern.x86_64
+0:eos-fuse-sysv-4.5.6-20190829163023gite72c345.el7.cern.x86_64
+0:eos-fusex-4.5.6-20190829163023gite72c345.el7.cern.x86_64
+0:eos-fusex-core-4.5.6-20190829163023gite72c345.el7.cern.x86_64
+0:eos-fusex-selinux-4.5.6-20190829163023gite72c345.el7.cern.x86_64
+0:eos-server-4.5.6-20190829163023gite72c345.el7.cern.x86_64
+0:eos-srm-4.5.6-20190829163023gite72c345.el7.cern.x86_64
+0:eos-test-4.5.6-20190829163023gite72c345.el7.cern.x86_64
+0:eos-testkeytab-4.5.6-20190829163023gite72c345.el7.cern.x86_64
 1:python2-xrootd-4.10.0-1.el7.*
 1:python3-xrootd-4.10.0-1.el7.*
 1:xrootd-4.10.0-1.el7.*