Remove enabled_backend entry from 00-config.conf

With webhooks we prevent the glance deploy unless a backend is specified
via customServiceConfig. It doesn't fail if replicas is set to 0, but in
general a backend must be specified.
This patch reinforce what already done by removing the enabled_backend
line from 00-configa.

Signed-off-by: Francesco Pantano <fpantano@redhat.com>

Author: fmount

templates/common/config/00-config.conf

@@ -18,7 +18,6 @@ max_logfile_size_mb=50
 log_rotation_type=size
 log_file = {{ .LogFile }}
 {{ end }}
-enabled_backends=default_backend:file
 # cache related parameters
 {{ if (index . "CacheEnabled") }}
 image_cache_dir = {{ .ImageCacheDir }}