Fix import of reports in ZIP files.

[jangrewe]

file_get_contents doesn't seem to play well with ZIP files unless it gets the absolute path to the archive.

[Xunnamius]

My fork has a further fix on top of this, namely: handling gz vs gzip both as gzip (and also fixing the regular expressions, which didn't escape out the periods) @ https://github.com/Xunnamius/DMARC-reports-analyzer