Reduce poudriere log retention to 30 days.

ansible/roles/poudriere/files/poudboot.bash

@@ -9,6 +9,7 @@ DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 : ${INFO_DIR:="/opt/poudriere/run_info"}
 : ${PORT_UPDATE_SECONDS:="86400"}
 : ${BUILD_SECONDS:="7200"}
+: ${LOG_RETENTION_DAYS:="30"}
 
 ############## Setup #########################
 
@@ -103,7 +104,7 @@ function cmd_start {
                     LASTBUILD=$(date +%s)
                     # Cleanup old unused dist files
                     poudriere distclean -y -p "$PORTS" -f /usr/local/etc/poudriere.d/$JAIL-$PORTS-$SET-pkglist
-                    poudriere logclean -y 180
+                    poudriere logclean -y "$LOG_RETENTION_DAYS"
                 fi
 
                 cat > "$TIMES_FILE" <<EOF