slapos_panel: ensure the url is relative to the web site, but without containing a //

master/bt5/slapos_panel/SkinTemplateItem/portal_skins/slapos_panel/Project_addSlapOSComputeNodeToken.py

-from urlparse import urljoin
+from urlparse import urljoin, urlparse
 
 portal = context.getPortalObject()
 person = portal.portal_membership.getAuthenticatedMember().getUserValue()
@@ -28,8 +28,10 @@ if slapos_master_web_url is None:
 
 # XXX this url is HARDCODED on the client side
 # and so, can not be modified
-request_url = urljoin(slapos_master_web_url, "Person_requestComputer")
-
+# ensure the url is relative to the web site, but without containing a //
+request_url = urljoin(urljoin(slapos_master_web_url,
+                              urlparse(slapos_master_web_url + '/').path.replace('//','/')),
+                      "Person_requestComputer")
 person.requestToken(request_url=request_url)
 access_token_id = context.REQUEST.get("token")