Adjust TYPO3 docs urls
https://docs.typo3.org/typo3cms/extensions/core/Changelog/7.4/Breaking-68001-RemovedExtJSCoreAndExtJSAdapters.html
=> https://docs.typo3.org/typo3cms/extensions/core/7.6/Changelog/7.4/Breaking-68001-RemovedExtJSCoreAndExtJSAdapters.html
(adding /7.6/
path segment)