Only inject DO_TOKEN when actually provided (#19866)

Signed-off-by: Martin Hanzík <martin@hanzik.com>

stable/external-dns/Chart.yaml

@@ -1,6 +1,6 @@
 apiVersion: v1
 name: external-dns
-version: 2.13.2
+version: 2.13.3
 appVersion: 0.5.17
 description: ExternalDNS is a Kubernetes addon that configures public DNS servers with information about exposed Kubernetes services to make them discoverable.
 keywords:

stable/external-dns/templates/deployment.yaml

@@ -222,12 +222,14 @@ spec:
         {{- end }}
         # DigitalOcean environment variables
         {{- if eq .Values.provider "digitalocean" }}
+        {{- if .Values.digitalocean.apiToken }}
         - name: DO_TOKEN
           valueFrom:
             secretKeyRef:
               name: {{ template "external-dns.fullname" . }}
               key: digitalocean_api_token
         {{- end }}
+        {{- end }}
         # Google environment variables
         {{- if eq .Values.provider "google" }}
         {{- if or .Values.google.serviceAccountSecret .Values.google.serviceAccountKey }}