[americanexpress] fix transaction type detection error

In case of volontary payments message is different than for auto-debit
case: "PAYMENT RECEIVED THROUGH MYBANK" vs "PAYMENT RECEIVED THROUGH
AUTOPAY".
But it still needs to be flagged as TYPE_CARD_SUMMARY
6 jobs for amex-multicard-split in 12 minutes and 42 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #25674
build:3

00:00:57

 
  Test
failed #25676
allowed to fail
lint:3

00:01:35

passed #25675
pyflakes:3

00:01:31

passed #25677
unittests:3

00:01:30

failed #25678
allowed to fail
unittests-modules:3

00:10:42

 
  Deploy
passed #25679
doc:3

00:01:02

 
Name Stage Failure
failed
lint:3 Test
=== [  0%] Getting file:///builds/sinopsysHK/weboob/modules
=== [100%] All modules are up-to-date.

Modules without tests: afer, ameli, amundi, banqueaccord, bforbank, bnpcards, bolden, bouygues, bp, caels, chronopost, cmb, cmmc, cmso, colisprive, colissimo, degiro, edf, ensap, genericnewspaper, gmf, lendosphere, linebourse, lucca, lunchr, materielnet, n26, nalo, netfinca, okc, oney, onlinenet, orange, ovh, pagesjaunes, peertube, redmine, relaiscolis, sogecartenet, tapatalk, ticketscesu, wiseed, yomoni

Modules without icons: avendrealouer, aviva, bnpcards, bnppere, bolden, btpbanque, capeasi, cices, cmes, deathbycaptcha, degiro, ekwateur, ensap, erehsbc, esalia, gmf, lendosphere, linebourse, lucca, lunchr, materielnet, meslieuxparis, nalo, netfinca, onlinenet, pradoepargne, sogecartenet, tapatalk, themisbanque, ticketscesu, trainline, wiseed

Modules for Python 2 only: airparif, allocine, amazonstorecard, apivie, asana, audioaddict, canalplus, carrefourbanque, cci, centquatre, cityscoot, colisprive, cpasbien, dailymotion, degiro, dhl, dpd, dresdenwetter, ensap, ganassurances, gls, groupama, guerrillamail, happn, hds, humanis, ideel, ilmatieteenlaitos, ina, inrocks, itella, journaldesfemmes, kickass, kiwibank, lacentrale, lampiris, lunchr, lyricsdotcom, lyricsplanet, mailinator, meslieuxparis, minutes20, myhabit, netfinca, okc, openedx, pagesjaunes, parolesmusique, parolesnet, paypal, phpbb, pixabay, playme, poivy, pradoepargne, presseurop, prixcarburants, radiofrance, residentadvisor, rmll, sachsen, t411, taz, ticketscesu, tinder, torrentz, transilien, vicsec, vicseccard, vine, virginradio, yahoo
ERROR: Job failed: exit code 1
failed
unittests-modules:3 Test
-----------------------------------------------------------------------
TOTAL 69972 45814 35%
----------------------------------------------------------------------
Ran 362 tests in 528.683s

FAILED (SKIP=103, errors=135, failures=30)
=== Total coverage ===
MODULES COVERAGE: 35%
ERROR: Job failed: exit code 1