Don't use global app for api / api4 tests (#7528)

* don't use global app for api / api4 tests

* put sleep back. we're gonna have to do some goroutine wrangling

* fix oauth test config assumptions

* jobs package, i'm comin' for you next

* app test fix

* try increasing sleep a little

app/server.go

@@ -222,5 +222,7 @@ func (a *App) StopServer() {
 
 	a.ShutDownPlugins()
 
+	a.Srv = nil
+
 	l4g.Info(utils.T("api.server.stop_server.stopped.info"))
 }