amavisd default props moved to nethserver-mail-filter. Refs #1870
/etc/amavisd.conf template: default content inspection type is "amavisd-after-queue" with all checks disabled. Refs #1870
/etc/postfix/master.cf template: default content inspection type is "amavisd-after-queue", connection limits are set only for type "amavisd-before-queue". Refs #1870
/postfix/master.cf template: moved 30amavisd-before-queue fragment to nethserver-mail-filter. Refs #1870