[FIX] website_forum: don't use span with style for forum

Forum sanitize the content before to be inserted in db.
So all tags style are removed...

Disabling the option styleWithSpan, will let summernote to use <b>, <u>, <i>
to allow the end user to change the style from an answer / question.

addons/website_forum/static/src/js/website_forum.js

@@ -225,8 +225,9 @@
             }
             $textarea.summernote({
                     height: 150,
-                    toolbar: toolbar
-                });
+                    toolbar: toolbar,
+                    styleWithSpan: false
+            });
             $form.on('click', 'button, .a-submit', function () {
                 $textarea.html($form.find('.note-editable').code());
             });