Remove promise return from function ApplicationService::changeProject({ gid, host })

[volterra79]

No more return promise is used when changeProject is run because location.replace(url) reload page

[Raruto]

Moved to v3.9 because I have the suspect that calling location.replace() the context change isn't so immediate and removing the promised return from the changeProject() function might break something else (ie. anything like changeProject().then(...)).

Remember to check better when we get closer to:

• Deprecate hooks ProjectsRegistry~setCurrentProject(project) and ProjectsRegistry~createProject(projectConfig) #320
• Migrate all jQuery promises to native ES6 Promise (ref: $.Deferred(), $.when(), $.get() and $.post()) #308