Fixed several possible nil pointer access issues.

src/app/spreed-speakfreely-server/sessions.go

@@ -83,12 +83,15 @@ func (sessions *Sessions) Patch(request *http.Request) (int, interface{}, http.H
 		error = true
 	}
 
+	var userid string
 	// Validate with users handler.
-	userid, err := sessions.users.handler.Validate(&snr, request)
+	if sessions.users.handler != nil {
+		userid, err = sessions.users.handler.Validate(&snr, request)
 		if err != nil {
 			error = true
 			log.Println("Session patch failed - users validation failed.", err)
 		}
+	}
 
 	// Make sure that we have a user.
 	if userid == "" {

src/app/spreed-speakfreely-server/users.go

@@ -263,7 +263,7 @@ func NewUsers(hub *Hub, mode, realm string, runtime phoenix.Runtime) *Users {
 	var err error
 
 	// Create handler based on mode.
-	if handler, err = users.createHandler(mode, runtime); err == nil {
+	if handler, err = users.createHandler(mode, runtime); handler != nil && err == nil {
 		users.handler = handler
 		// Register handler Get at the hub.
 		users.hub.useridRetriever = func(request *http.Request) (userid string, err error) {