plugins,telit: SWPKGV parsing needs more permissive regex

In some cases the "base" software package string does not have the currently expected format of \d{2}.\d{2}.\d{3}. Specifically the last triplet of characters might not be digits. For example a valid version string might be 25.20.-04, which the current regex is unable to parse.

This change replace the previous regex with one less restrictive, checking only the first part of the version's format.

The correspondent tests also need a fix to avoid false failures.