Jenkins start-up script to enable images, links, javascript

startup-properties.groovy

# Step 1: In jenkins home directory create folder with name "init.groovy.d"
# Step 2: under above folder create file with name "startup-properties.groovy"

# Step 3: Include following code in it

import jenkins.model.Jenkins
import java.util.logging.LogManager

System.setProperty("hudson.model.DirectoryBrowserSupport.CSP", "sandbox allow-same-origin allow-popups allow-scripts; default-src *; img-src 'self' data:; style-src * http://* 'unsafe-inline' 'unsafe-eval'; script-src 'self' http://* 'unsafe-inline' 'unsafe-eval'");