[FIX] snailmail: Fix a CSS selector

One of the selector didn't work due to a space before the classes and
prevented the fix from working. This fixes it in my tests.

closes odoo/odoo#108244

X-original-commit: 334c79409a02beedb317d132f76005521e407bc7
Signed-off-by: Louis Baudoux (lba) <lba@odoo.com>
Signed-off-by: Solan Delvenne (sode) <sode@odoo.com>

addons/snailmail/static/src/scss/snailmail_external_layout_asset.scss

@@ -40,15 +40,11 @@ div .address.row > div[name="address"] {
 }
 
 /* Follow-up Letters */
-div .pt-5:empty {
-    display: none;
-}
-
 div .row.fallback_header {
     margin-top: -4mm !important;
     height: 68mm !important;
     width: 117% !important;
-    > div .col-5.offset-7 {
+    > div.col-5.offset-7 {
         background-color: #ffffff;
         margin-left: 48.5% !important;
         position: relative !important;