Fix duplicated log entries pushed by Promtail sidecar

The Promtail sidecar was pushing all Gerrit logs twice. The reason
was, that the client URL provided by the command line was not
overwriting the one in the config, thereby creating two client entries
with the same Loki URL.

Change-Id: Icd6bb9a93a6a2072efe34886091d93859055e697
diff --git a/helm-charts/gerrit-replica/templates/promtail.configmap.yaml b/helm-charts/gerrit-replica/templates/promtail.configmap.yaml
index 4ccd869..0e6beec 100644
--- a/helm-charts/gerrit-replica/templates/promtail.configmap.yaml
+++ b/helm-charts/gerrit-replica/templates/promtail.configmap.yaml
@@ -12,8 +12,7 @@
     positions:
       filename: /var/gerrit/logs/promtail-positions.yaml
 
-    clients:
-      - url: {{ .Values.promtailSidecar.loki.url }}/loki/api/v1/push
+    client:
         tls_config:
           insecure_skip_verify: {{ .Values.promtailSidecar.tls.skipVerify }}
           {{- if not .Values.promtailSidecar.tls.skipVerify }}