New upstream version 2021.4

apidoc/html/index.html

@@ -14,7 +14,7 @@
 <div class="titlepage">
 <div>
 <div><table class="navigation" id="top" width="100%" cellpadding="2" cellspacing="0"><tr><th valign="middle"><p class="title">OSTree API references</p></th></tr></table></div>
-<div><p class="releaseinfo">for OSTree 2021.3</p></div>
+<div><p class="releaseinfo">for OSTree 2021.2</p></div>
 </div>
 <hr>
 </div>