[FIX] web: improve visual glitch for 'many2many_tags' field widget on…

… settings view

 - For 'res.config.setting' view, when there is a field with
'many2many_tags' widget, a drop-down is not displayed
properly. (For example, see 'default_cashbox_lines_ids'
field from point_of_sale module)

 - This commit fixes the above visual glitch by properly displaying
the field having 'many2many_tags' widget on settings view.

Task id - 1935608

addons/web/static/src/scss/form_view.scss

@@ -744,6 +744,10 @@
             .o_field_widget {
                 width: 50%;
                 flex: 0 0 auto;
+
+                &.o_field_many2manytags > .o_field_widget {
+                    flex: 1 0 50px;
+                }
             }
             button.btn-link:first-child {
                 padding-left: 0;