[FIX] website_forum: enlarge answer textarea

This commit permits to enlarge the answer textarea in the forum.

Steps to reproduce the "issue" resolved by this commit:
- Go to /forum
- Click on a thread
- Click on "Answer"

=> The textarea is too small to write a long answer.

task-2865782

closes odoo/odoo#124740

X-original-commit: faaf76c0043d72da7cec587c327d6b508b2ca0fd
Signed-off-by: Dieleman Guillaume (gdi) <gdi@odoo.com>
Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>

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

@@ -132,6 +132,7 @@ publicWidget.registry.websiteForum = publicWidget.Widget.extend({
                 },
                 resizable: true,
                 userGeneratedContent: true,
+                height: 350,
             };
             options.allowCommandLink = hasFullEdit;
             options.allowCommandImage = hasFullEdit;