adjust bindings-forwarder deployment template (#529)

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## What
When using extraVolumes and extraVolumeMounts the indentation was a little bit off which was causing the templating to generate invalid yaml.

## How
*Describe the solution*
change the indentation and add dashes so there's no blank lines.

Before:
```
        - name: SSL_CERT_DIR
          value:
            /etc/ssl/certs/ngrok
        volumeMounts:

          - mountPath: /etc/ssl/certs/ngrok
            name: ca-certs
            readOnly: true
        - name: ngrok-ca
          mountPath: /etc/ssl/certs/ngrok
          readOnly: true
```

## Breaking Changes
none

helm/ngrok-operator/templates/bindings-forwarder/deployment.yaml

@@ -94,7 +94,7 @@ spec:
         {{- end }}
         {{- if .Values.extraVolumeMounts  }}
         volumeMounts:
-        {{ toYaml .Values.extraVolumeMounts | nindent 10 }}
+        {{- toYaml .Values.extraVolumeMounts | nindent 8 }}
         - name: ngrok-ca
           mountPath: /etc/ssl/certs/ngrok
           readOnly: true
@@ -106,7 +106,7 @@ spec:
         {{- end }}
         {{- if .Values.lifecycle }}
         lifecycle:
-        {{ toYaml .Values.lifecycle | nindent 10 }}
+        {{- toYaml .Values.lifecycle | nindent 10 }}
         {{- end }}
         livenessProbe:
           httpGet:
@@ -124,7 +124,7 @@ spec:
         {{- toYaml .Values.resources | nindent 10 }}
       {{- if .Values.extraVolumes }}
       volumes:
-        {{ toYaml .Values.extraVolumes | nindent 6 }}
+        {{- toYaml .Values.extraVolumes | nindent 8 }}
         - name: ngrok-ca
           configMap:
             name: ngrok-intermediate-ca