Merge remote-tracking branch 'origin/debian/buster' into proposed-updates/ritesh/updates-buster.apertis/v2021-updates

net-snmp (5.7.3+dfsg-5+deb10u2) buster; urgency=high

• snmpd: Add cacheTime and execType flags to EXTEND-MIB. Previous security release made EXTEND-MIB read-only which meant it was not possible to set the timeout of the cache. This patch allows the administrator to set the value in the snmpd.conf file. Closes: #969508