fix(documentation) fix reference to the old documentation in UPGRADE.md and README.md

Signed-off-by: Benoit Mortier <benoit.mortier@opensides.be>

README.md

@@ -87,7 +87,7 @@ If you like [FusionDirectory][FusionDirectory] and would like to [donate][donate
 
 [FusionDirectory]: https://www.fusiondirectory.org/
 
-[fusiondirectory-install]: http://documentation.fusiondirectory.org/en/documentation_admin
+[fusiondirectory-install]: https://fusiondirectory-user-manual.readthedocs.io/en/1.3/install/index.html
 
 [get help]: https://www.fusiondirectory.org/contact-us/
 

UPGRADE.md

@@ -3219,7 +3219,7 @@ fusiondirectory-insert-schema -m /etc/ldap/schema/fusiondirectory/weblink-fd.sch
 
 [php-cas]: http://packages.ubuntu.com/trusty/all/php-cas/download
 
-[repo-urls]: https://documentation.fusiondirectory.org/en/dl_install
+[repo-urls]: https://fusiondirectory-user-manual.readthedocs.io/en/1.3/install/index.html
 
 ---
 * Further information
@@ -3227,7 +3227,7 @@ fusiondirectory-insert-schema -m /etc/ldap/schema/fusiondirectory/weblink-fd.sch
 To improve this piece of software, please report all kind of errors using the bug tracker
 on https://gitlab.fusiondirectory.org
 
-Documentation: https://documentation.fusiondirectory.org/
+Documentation: https://fusiondirectory-user-manual.readthedocs.io/en/1.3/index.html
 Mailinglist:   https://lists.fusiondirectory.org/
 Irc:           #fusiondirectory on freenode