package/dovecot: bump version to 2.3.21

Release notes:
https://dovecot.org/mailman3/archives/list/dovecot-news@dovecot.org/thread/KYDR7WWPEQOBZA3IA4NL5XDSLODZLG6N/

Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/dovecot/dovecot.hash

@@ -1,5 +1,5 @@
 # Locally computed after checking signature
-sha256  caa832eb968148abdf35ee9d0f534b779fa732c0ce4a913d9ab8c3469b218552  dovecot-2.3.20.tar.gz
+sha256  05b11093a71c237c2ef309ad587510721cc93bbee6828251549fc1586c36502d  dovecot-2.3.21.tar.gz
 sha256  319a9830aab406109cd67cb45496587566a8123203d66d037b209ca3e13de02a  COPYING
 sha256  dc626520dcd53a22f727af3ee42c770e56c97a64fe3adb063799d8ab032fe551  COPYING.LGPL
 sha256  52b8c95fabb19575281874b661ef7968ea47e8f5d74ba0dd40ce512e52b3fc97  COPYING.MIT

package/dovecot/dovecot.mk

@@ -5,7 +5,7 @@
 ################################################################################
 
 DOVECOT_VERSION_MAJOR = 2.3
-DOVECOT_VERSION = $(DOVECOT_VERSION_MAJOR).20
+DOVECOT_VERSION = $(DOVECOT_VERSION_MAJOR).21
 DOVECOT_SITE = https://dovecot.org/releases/$(DOVECOT_VERSION_MAJOR)
 DOVECOT_INSTALL_STAGING = YES
 DOVECOT_LICENSE = LGPL-2.1, MIT, Public Domain, BSD-3-Clause, Unicode-DFS-2015