Bug 1869519 - Fix EdAdvancedEdit.xhtml dialog height on macOS. r=mkmelin

Differential Revision: https://phabricator.services.mozilla.com/D196721

--HG--
extra : amend_source : 57cddfdae7a7c72eb6d966778bf2fa5236e98c8e
extra : absorb_source : a06ddca175a402fef11e06e89ec7439bebe723ef

mail/components/compose/content/dialogs/EdAdvancedEdit.xhtml

@@ -8,7 +8,7 @@
   xmlns="http://www.w3.org/1999/xhtml"
   xmlns:xul="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
   xmlns:html="http://www.w3.org/1999/xhtml"
-  style="min-width: 40em"
+  style="min-width: 40em; min-height: 40em"
   scrolling="false"
   lightweightthemes="true"
 >