Fix timeout detection

The XML processor was only noting timeouts for "SYN Stealth Scan"
(`-sS`). However, full scans default to "Connect Scan" (`-sT`)
since 10e3637a540a. Change the XPath to trigger for any `<taskend>`
element where the `extrainfo` attribute contains "timed out".
Merge pull request #11 from peter-mtso/fix_timeout_detection

Fix timeout detection