circleci: Isolate centos-specific setup

Not all RPM-based distributions are EPEL consumers.

Better diff with the --ignore-all-space option.

.circleci/make-rpm-packages.sh

@@ -13,13 +13,12 @@ elif [ -z "$PARAM_DIST" ]; then
     exit 1
 fi
 
-yum install -y epel-release
-
 if [ "$PARAM_DIST" = centos ]; then
-  if [ "$PARAM_RELEASE" = 8 ]; then
-      dnf install -y 'dnf-command(config-manager)'
-      yum config-manager --set-enabled powertools
-  fi
+    if [ "$PARAM_RELEASE" = 8 ]; then
+        dnf install -y 'dnf-command(config-manager)'
+        yum config-manager --set-enabled powertools
+    fi
+    yum install -y epel-release
 fi
 
 yum install -y rpm-build yum-utils