explicitly set root user for RHEL containers (#208)

mq-advanced-server-rhel/mq-buildah.sh

@@ -106,6 +106,7 @@ buildah config \
   --env LANG=en_US.UTF-8 \
   --env LOG_FORMAT=basic \
   --entrypoint runmqserver \
+  --user root \
   $ctr_mq
 buildah unmount $ctr_mq
 buildah commit $ctr_mq $tag

mq-advanced-server-rhel/mqdev-buildah.sh

@@ -80,6 +80,7 @@ buildah config \
   --env MQ_ADMIN_PASSWORD=passw0rd \
   --env MQ_DEV=true \
   --entrypoint runmqdevserver \
+  --user root \
   $ctr_mq
 buildah unmount $ctr_mq
 buildah commit $ctr_mq $tag