build report: handle editor.log with timetamps

[unitycoder]

apparently there is -timestamp editor argument, that adds timestamps to log file also,
that might break build report parsing..
https://forum.unity.com/threads/log-files-timestamping.823821/#post-8622885

[unitycoder]

actually it might still break, if -timestamps value is not found from current log

[unitycoder]

just as a reference, good tool
https://github.com/FronkonGames/Build-History