Fix issue #1437 where FileLog::pruneDate() didn't prune anything if the given date was prior to the first last log entry date.
Fix issue #1437 where FileLog::pruneDate() didn't prune anything if the given date was prior to the first last log entry date.

fezde/ProcessWire,rusjoan/poly-hackaton,ryancramerdesign/ProcessWire,fezde/ProcessWire,ryancramerdesign/ProcessWire,rusjoan/poly-hackaton,ryancramerdesign/ProcessWire,rusjoan/poly-hackaton,fezde/ProcessWire,rusjoan/poly-hackaton,ryancramerdesign/ProcessWire,rusjoan/poly-hackaton,fezde/ProcessWire,fezde/ProcessWire,ryancramerdesign/ProcessWire