fix powertools dep in centos 8

docker/centos8/Dockerfile

@@ -16,7 +16,7 @@ RUN dnf -y install https://download.postgresql.org/pub/repos/yum/reporpms/EL-8-x
 # enable epel repo
 RUN dnf -y install https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm
 # enable powertools repos
-RUN dnf -y install 'dnf-command(config-manager)' && dnf -y config-manager --set-enabled PowerTools
+RUN dnf -y install 'dnf-command(config-manager)' && dnf -y config-manager --set-enabled powertools
 
 # set php to remi 7.4
 RUN dnf -y module reset php && dnf -y module enable php:remi-7.4