Change in default languages for mails

 * "en fr" for new elections
 * "en" for old elections that don't have the property set

src/web/web_common.ml

@@ -232,7 +232,7 @@ let available_languages = ["en"; "fr"; "de"]
 
 let get_languages xs =
   match xs with
-  | None -> available_languages
+  | None -> ["en"]
   | Some xs -> xs
 
 let string_of_languages xs =

src/web/web_site.ml

@@ -327,7 +327,7 @@ let create_new_election owner cred auth =
     e_auth_config;
     e_cred_authority;
     e_trustees = None;
-    e_languages = None;
+    e_languages = Some ["en"; "fr"];
   } in
   let question = {
     q_answers = [| "Answer 1"; "Answer 2"; "Blank" |];