fix a bug that could prevent user to selet their payment methods

frontend/locales/en.json

@@ -160,6 +160,7 @@
     "and/or": "and/or",
     "form name recommandation": "recommendation: Contract <contract-type> (Example: Pork-Lamb Contract)",
     "submit contract": "submit contract",
+    "submit": "submit",
     "example in user forms": "example in user contract form",
     "occasional product": "occasional product",
     "recurrent product": "recurrent product",

frontend/locales/fr.json

@@ -160,6 +160,7 @@
     "and/or": "et/ou",
     "form name recommandation": "recommandation : Contrat <contract-type> (Exemple : Contrat Porc-Agneau)",
     "submit contract": "envoyer le contrat",
+    "submit": "envoyer",
     "example in user forms": "exemple dans le formulaire à destination des amapiens",
     "occasional product": "produit occasionnel",
     "recurrent product": "produit récurrent",