[ameli] Detect a new kind of error page

When failing the CSRF token, an error page is thrown. We detect it and
send a BrowserUnavailable exception
7 jobs for ameli_fix_csrf in 19 minutes and 33 seconds (queued for 29 minutes and 57 seconds)
latest
Status Job ID Name Coverage
  Build
passed #28733
build:3

00:02:03

 
  Test
passed #28736
load-modules:3

00:01:51

passed #28734
pyflakes:3

00:01:57

passed #28735
pyflakes-strict:3

00:02:01

passed #28737
unittests:3

00:01:56

failed #28738
allowed to fail
unittests-modules:3

00:10:51

 
  Deploy
passed #28739
doc:3

00:02:33

 
Name Stage Failure
failed
unittests-modules:3 Test
-----------------------------------------------------------------------
TOTAL 70495 41370 41%
----------------------------------------------------------------------
Ran 370 tests in 482.902s

FAILED (SKIP=112, errors=155, failures=31)
=== Total coverage ===
MODULES COVERAGE: 41%
ERROR: Job failed: exit code 1