Correct broken links in the following guides:

https://access.redhat.com/documentation/en-us/red_hat_jboss_enterprise_application_platform/7.3/html-single/patching_and_upgrading_guide/index

Refer to the following guide for information about missing links - https://docs.google.com/spreadsheets/d/1W18QFlvJo3P9x1UpdqZ059ZMRQUYwAGdNYSddyj6EJY/edit#gid=1449882881

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For 7.3.z there are 8 combined missing links.

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