On some linux servers system.sw.packages.get is unsupported with error "[Sw] Failed to parse 'dpkg --get-selections' output, err: strconv.ParseUint: parsing "": invalid syntax"

Steps to reproduce:

1. Login via ssh to linux server
2. Switch to root
3. Execute "zabbix_agent2 -c /etc/zabbix/zabbix_agent2.conf -t system.sw.packages.get -v"

Result:
See log files ubuntu_system_sw_packages_get.log / debian_system_sw_packages_get.log
Output of "dpkg --get-selections" and "LC_ALL=C dpkg-query -W -f='${Status},${Package},${Version},${Architecture},${Installed-Size}\n'", from sw module (sw_linux.go) in attachments.
Item also not supported in monitoring via latest linux os template.
However, item system.sw.packages is working fine.

Expected:
The item is supported and work fine.