Bug 1607580 - Make the download folder box height the same as the Browse... button r=johannh

Differential Revision: https://phabricator.services.mozilla.com/D59011

--HG--
extra : moz-landing-system : lando

browser/themes/shared/incontentprefs/preferences.inc.css

@@ -303,6 +303,7 @@ button > hbox > label {
 
 #downloadFolder {
   -moz-box-flex: 1;
+  margin-block: 4px;
   margin-inline-start: 0;
   padding-inline-start: 30px;
   background-repeat: no-repeat;