erp5/test: give more time for ERP5 to be ready

now that promises are satisfied, we don't retry slapos node instance
again and again, so this test starts earlier and we need to wait longer
for ERP5 to be ready.

software/erp5/test/test/test_erp5.py

@@ -50,7 +50,7 @@ class TestPublishedURLIsReachableMixin(object):
     # with 503 Service Unavailable.
     # If we can move the "create site" in slapos node instance, then this retry loop
     # would not be necessary.
-    for i in range(1, 20):
+    for i in range(1, 60):
       r = requests.get(url, verify=False) # XXX can we get CA from caucase already ?
       if r.status_code == requests.codes.service_unavailable:
         delay = i * 2