Adding if Condition for checksum

[vemulaanvesh]

What does this PR do?

• Adding a provision to turn off or on checksum

• When i am applying JCASC via GH PR, every time when PR get merged, Jenkins is througing 111 error for nearly 30-40 sec (which means downtime for 30-40 sec).

• so we want to turn off checksum and restart jenkins during maintaince window.

• As this is a extra provision to users i feel this should be a good option

If you modified files in the ./charts/jenkins/ directory, please also include the following:

Submitter checklist

Beta Give feedback

1. I bumped the "version" key in ./charts/jenkins/Chart.yaml.
2. I added a new changelog entry to ./charts/jenkins/CHANGELOG.md.
3. I followed the technical requirements.
4. I ran .github/helm-docs.sh from the project root.

Special notes for your reviewer

[timja]

• When i am applying JCASC via GH PR, every time when PR get merged, Jenkins is througing 111 error for nearly 30-40 sec (which means downtime for 30-40 sec).

If you use auto reload you won't have that issue:

helm-charts/charts/jenkins/templates/config.yaml

Lines 65 to 66 in d1423c7

	# Only add config to this script if we aren't auto-reloading otherwise the pod will restart upon each config change:
	{{- if .Values.controller.JCasC.defaultConfig }}