[FIX] portal: rtl is active even without website

Steps to reproduce:
- install sales
- install a language with rtl support
- set the installed language as preffered language for current user
- preview any sale order/quotation on the portal

Previous behavior:
the portal is not showed right to left

Current behavior:
rtl is working a intended

opw-2167151

closes odoo/odoo#43737

X-original-commit: 2855ac7a
Signed-off-by: Nicolas Martinelli (nim) <nim@odoo.com>

addons/portal/static/src/scss/portal.scss

@@ -24,6 +24,12 @@ $o-portal-bg-color: desaturate($gray-200, 100%);
 $o-portal-use-default-colors: $body-bg == $o-portal-default-body-bg;
 
 // Frontend general
+body {
+    // Set frontend direction that will be flipped with
+    // rtlcss for right-to-left text direction.
+    direction: ltr;
+}
+
 header {
     .navbar-brand {
         flex: 0 0 auto;