release 2.2.4 to replace 2.2.3 ASAP

git-svn-id: https://plugins.svn.wordpress.org/footnotes/trunk@2440595 b8457f37-d9ea-0310-8a92-e5e31aec5664

readme.txt

@@ -4,7 +4,7 @@ Tags: footnote, footnotes, bibliography, formatting, notes, Post, posts, referen
 Requires at least: 3.9
 Tested up to: 5.6
 Requires PHP: 5.6
-Stable Tag: 2.2.3
+Stable Tag: 2.2.4
 License: GPLv3 or later
 License URI: http://www.gnu.org/licenses/gpl-3.0.html
 
@@ -80,6 +80,10 @@ Visit this swift write-up from a **footnotes** user by the name of **Southwest**
 
 == Changelog ==
 
+= 2.2.4 =
+- Bugfix: Reference container: Backlink symbol selection: moved back to previous tab “Referrers and tooltips”
+- Bugfix: Custom CSS: make inserting existing in header depend on migration complete checkbox status
+
 = 2.2.3 =
 - Bugfix: Custom CSS: insert new in header after existing