[FIX] mail: navigable list loading with gap between icon and label

Before this commit, when navigable list is loading data of
suggestions, the showing of "loading..." had label and icon
next to each other without any gap.

This commit adds a small gap between icon and label, so it looks
nicer.

closes odoo/odoo#127304

X-original-commit: 0aaab95cd39c50d9320dbec0417773497ebc0fcc
Signed-off-by: Matthieu Stockbauer (tsm) <tsm@odoo.com>
Signed-off-by: Alexandre Kühn (aku) <aku@odoo.com>

addons/mail/static/src/core/common/navigable_list.xml

@@ -5,7 +5,7 @@
         <div class="o-mail-NavigableList bg-white m-0 p-0" t-ref="root" t-att-class="props.class">
             <div t-if="show" class="o-open border" t-on-mousedown.prevent="">
                 <div t-if="state.isLoading" class="o-mail-NavigableList-item">
-                    <a href="#" class="d-flex align-items-center w-100 py-2 px-4">
+                    <a href="#" class="d-flex align-items-center w-100 py-2 px-4 gap-1">
                         <i class="fa fa-spin fa-circle-o-notch"/>
                         <t t-esc="props.placeholder"/>
                     </a>