Update some Gitlab URLs for applications

Assertion-Manager/installation.md

Authentication-Simulator/installation.md

CDA-Generator/installation.md

Demographic-Data-Server/installation.md

Gazelle-HL7-Validator/installation.md

Gazelle-Security-Suite/installation.md

Gazelle-Webservice-Tester/installation.md

HPD-Simulator/installation.md

Order-Manager/installation.md

Patient-Manager/installation.md

Proxy/installation.md

SVS-Simulator/installation.md

SVS-Simulator/release-note.md

Schematron-Validator/installation.md

XDStar-Client/installation.md

XDW-Simulator/installation.md