Fix piped deployment to use the created service account only if it wa…

…s created (#1993)

**What this PR does / why we need it**:

**Which issue(s) this PR fixes**:

Fixes #

**Does this PR introduce a user-facing change?**:
<!--
If no, just write "NONE" in the release-note block below.
-->
```release-note
NONE
```

This PR was merged by Kapetanios.

manifests/piped/templates/deployment.yaml

@@ -19,7 +19,9 @@ spec:
         sidecar.istio.io/inject: "false"
         rollme: {{ randAlphaNum 5 | quote }}
     spec:
+      {{- if .Values.serviceAccount.create -}}
       serviceAccountName: {{ include "piped.serviceAccountName" . }}
+      {{- end }}
       containers:
         - name: piped
           image: "{{ .Values.image.repository }}:{{ .Chart.AppVersion }}"