Changelog for 2.308

What's new in 2.308 (2021-08-24)

• Use SVGs over PNGs for the sidebar when possible. Breadcrumb bar/logo/menu items are now correctly aligned on the left together. Move old war/images folder to webapp so they can be used in frontend - the SVGs are now in the webapp/images/svgs folder. (pull 5663)
• Update appearance for feed bar and description button to be modern and consistent. (pull 5664)
• When the buildWithParameter API is called, if the requests with the same parameters in the queue are merged, the http response code of the request uses a more appropriate 303(see other) instead of 201(created). (issue 66105)
• Warn about use of master in a label expression when that's no longer in use. (pull 5674)
• Use full URL character encoding for the generated inbound agent launch string. (pull 5636)
• Use the JVM's default keystore type for the Jenkins server when terminating TLS connections within Jenkins. Used if Jenkins is started with the --httpsPort argument. Winstone 5.21: Update Jetty from 9.4.42.v20210604 to Jetty 9.4.43.v20210629. (pull 5670, issue 66379, Winstone 5.20 changelog, Winstone 5.21 changelog, Jetty 9.4.43 changelog)
• Developer: Bump spring-security-bom from 5.5.1 to 5.5.2. (pull 5672, Spring project spring-security 5.5.2 release notes)