Fix Date vs. Last-Modified header issue in DefaultRevalidation.php.
Fix Date vs. Last-Modified header issue in DefaultRevalidation.php.

rsauvatinet/guzzle3,dshafik/guzzle,Naktibalda/guzzle,Briareos/guzzle,wherefortravel/guzzle,duyhuynhngoc/guzzle,EdgarPE/guzzle,lahmizzar/guzzle,guzzle/guzzle3,roundpartner/guzzle3,justincy/guzzle,WebSeed/guzzle,atrauzzi/guzzle,videni/guzzle,Naktibalda/guzzle,michabbb-backup/guzzle,dawehner/guzzle,BostjanOb/guzzle,Briareos/guzzle,kminh/guzzle3,jabong/guzzle3,guzzle/guzzle3,SharpSpring/guzzle3,Tobion/guzzle,cenxun/guzzle,kkopachev/guzzle,sahat/guzzle,stefanruijsenaars/guzzle,legovaer/guzzle3,chengky/guzzle,jabong/guzzle3,nazo/guzzle,stea4lth/guzzle,ehough/guzzle,videni/guzzle,barryvdh/guzzle3,mrm/guzzle,Brunty/guzzle,michabbb-backup/guzzle,SharpSpring/guzzle3,Tobion/guzzle,staylor/guzzle,lahmizzar/guzzle,wulftone/guzzle,duyhuynhngoc/guzzle,rsauvatinet/guzzle3,mortenhauberg/guzzle,grokify/guzzle,hussainweb/guzzle,BostjanOb/guzzle,ryanhughes/guzzle,ryanhughes/guzzle,phlogisticfugu/guzzle,mikicaivosevic/guzzle,kkopachev/guzzle,guzzle/guzzle,stefanruijsenaars/guzzle,checat/guzzle,Tony133/guzzle,dawehner/guzzle,legovaer/guzzle3,stea4lth/guzzle,phlogisticfugu/guzzle,nazo/guzzle,guzzle/guzzle,rajaehtesham/guzzle,mustafavelioglu/guzzle,dshafik/guzzle,WebSeed/guzzle,mubassirhayat/guzzle,justincy/guzzle,paveljanda/guzzle,Rinat-wc/guzzle,mustafavelioglu/guzzle,mortenhauberg/guzzle,jeskew/guzzle,thinsoldier/guzzle,Rinat-wc/guzzle,javierTerry/guzzle,roundpartner/guzzle3,kminh/guzzle3,barryvdh/guzzle3,vrkansagara/guzzle,sulfo/guzzle,Tony133/guzzle,ehough/guzzle,mrm/guzzle,rajaehtesham/guzzle,hussainweb/guzzle,dawehner/guzzle,chengky/guzzle,thinsoldier/guzzle,atrauzzi/guzzle,wulftone/guzzle,jeskew/guzzle,Brunty/guzzle,paveljanda/guzzle,staylor/guzzle,vrkansagara/guzzle,checat/guzzle,javierTerry/guzzle,wherefortravel/guzzle,mikicaivosevic/guzzle,cenxun/guzzle,sulfo/guzzle,grokify/guzzle,EdgarPE/guzzle