Merge branch '7.10.3' of https://gitlab.open-xchange.com/benedikt.kroening/ox-installer into 7.10.3

lib/setup.bash

@@ -805,11 +805,15 @@ function preInstallActions {
         echo "mysql mysql-server/root_password_again string ${DATABASE_ROOT_PASS}" | debconf-set-selections
     elif [[ true == "${ANY_RHEL}" ]] || [[ true == "${ANY_CENTOS}" ]]; then
         ADDITIONAL_PACKAGES="${ADDITIONAL_PACKAGES} nc"
-        echo ""
     fi
 
     if [[ "${INSTALL_TYPE}" == *"docker"* ]]; then
-        echo ""
+        if [[ true == "${ANY_CENTOS}" ]]; then
+            echo "Adding epel repository for additional packages ..."
+            yum install epel-release -y
+        fi
+
+        echo "Installing supervisor for service management ..."
         ADDITIONAL_PACKAGES="supervisor ${ADDITIONAL_PACKAGES}"
     fi