Add python2-xrootd to excluded packages list for the XRootd testing image

Dockerfile_xrd_testing

@@ -44,7 +44,7 @@ ADD cc7_xrd_testing_artifacts ${EOSREPODIR}
 
 RUN createrepo ${EOSREPODIR}; \
     echo -e "[eos-artifacts]\nname=EOS artifacts\nbaseurl=file://${EOSREPODIR}\ngpgcheck=0\nenabled=1\npriority=1" >> /etc/yum.repos.d/eos.repo; \
-    yum -y --nogpg --enablerepo=xrootd-testing --setopt="eos-depend.exclude=xrootd*" install \
+    yum -y --nogpg --enablerepo=xrootd-testing --setopt="eos-depend.exclude=xrootd*,python2-xrootd*" install \
     eos-server eos-testkeytab eos-archive eos-client \
     eos-debuginfo eos-fuse eos-fusex eos-test eos-ns-inspect