Update fluentbit-fluentBit.yaml to address issue 1635

When adding imagePullSecrets in fluentbit-fluentBit.yaml, test should be with an "with" instead of a "if" to have the local scope when later using "."
See issue #1635 

Signed-off-by: g1franc <guillaume.francois55@gmail.com>

Author: g1franc

charts/fluent-operator/templates/fluentbit-fluentBit.yaml

@@ -17,7 +17,7 @@ spec:
   dnsPolicy: ClusterFirstWithHostNet
   {{- end }}
   image: {{ template "fluent-operator.image" (tuple .Values.fluentbit.image "") }}
-  {{- if .Values.fluentbit.imagePullSecrets }}
+  {{- with .Values.fluentbit.imagePullSecrets }}
   imagePullSecrets:
     {{- toYaml . | nindent 4 }}
   {{- end }}