upgrade: 2.4 - HOME is no longer used with LDA

Author: sirainen

docs/installation/upgrade/2.3-to-2.4.md

@@ -137,6 +137,8 @@ https://github.com/dovecot/tools/blob/main/dovecot-2.4.0-example-config.tar.gz
 
 <!-- @include: include/2.4-doveadm.inc -->
 
+<!-- @include: include/2.4-lda.inc -->
+
 <!-- @include: include/2.4-exim.inc -->
 
 <!-- @include: include/2.4-other.inc -->

docs/installation/upgrade/include/2.4-lda.inc

@@ -0,0 +1,5 @@
+### LDA
+
+`HOME` environment is no longer used. (It was previously used when `-d`
+parameter was not given.) You can now use it by explicitly giving
+`-o mail_home=$HOME` parameter.