[FIX] web: settings view, remove unnecessary gap

This gap was initially introduced to increase space between section but
was not triggered correctly and, ultimately, not strictly necessary.

task-2579123

addons/web/static/src/legacy/scss/base_settings.scss

@@ -108,10 +108,6 @@
             overflow: auto;
 
             > .app_settings_block {
-                &:not(.o_hidden) {
-                    padding-bottom: 30px;
-                }
-
                 h2 {
                     margin: 0 0 !important;
                     @include o-base-settings-horizontal-padding(.4rem);