[FIX] mail: trim '()' characters

In commit 07425d407f a trim of some special characters was introduced
to prevent a crash. This was necessary in v9, but it is not in v10.

opw-703465

addons/mail/static/src/js/utils.js

@@ -130,7 +130,6 @@ var accented_letters_mapping = {
     'oe': 'œ',
     'u': '[ùúûűü]',
     'y': '[ýÿ]',
-    ' ': '[()\\[\\]]',
 };
 function unaccent (str) {
     _.each(accented_letters_mapping, function (value, key) {