fix last_modified tests failing on OSX 10.5 with 1.8.7 due to Time.httpdate limitations
fix last_modified tests failing on OSX 10.5 with 1.8.7 due to Time.httpdate limitations

Signed-off-by: Konstantin Haase <a90ceb496d9228fe419696e09c742e68f13c38e0@googlemail.com>

JonRowe/sinatra,bmizerany/sinatra,sethuster/sinatra,miyazawatomoka/sinatra,marocchino/sinatra,kyontan/sinatra,trexnix/sinatra,wzheng1/sinatra,porras/sinatra,QLGu/sinatra,lastcat/sinatra,ryanshaw/sinatra,gferguson-gd/sinatra,QLGu/sinatra,ksw2599/sinatra,burningTyger/sinatra,laplaceliu/sinatra,porras/sinatra,mwpastore/sinatra,nju520/sinatra,lastcat/sinatra,burningTyger/sinatra,sinatra/sinatra,autopp/sinatra,dariubs/sinatra,DoraALin/sinatra,twanies/sinatra,RosenDimov/sinatra,siberianbear/sinatra,howtolearntocode/sinatra,miyazawatomoka/sinatra,davydovanton/sinatra,cyberid41/sinatra,kumji/sinatra,nicoayala/sinatra,Callygraphy/morrissey,emiliocorpus/sinatra,siberianbear/sinatra,ganmacs/sinatra,midorineko/sinatra,jkowens/sinatra,Wirachmat/sinatra,Wirachmat/sinatra,kgrz/sinatra,RosenDimov/sinatra,wzheng1/sinatra,jkowens/sinatra,defsprite/sinatra,DoraALin/sinatra,ABaldwinHunter/sinatra-classic,Rayheng/sinatra,guidohcosta/sinatra,guidohcosta/sinatra,laplaceliu/sinatra,emiliocorpus/sinatra,ksw2599/sinatra,ganmacs/sinatra,d-bot/sinatra,midorineko/sinatra,nicoayala/sinatra,autopp/sinatra,JonMidhir/sinatra,defsprite/sinatra,d-bot/sinatra,Rayheng/sinatra,gferguson-gd/sinatra,mwpastore/sinatra,ktw1222/sinatra,burningTyger/sinatra,jenalgit/sinatra,jkowens/sinatra,jenalgit/sinatra,JonMidhir/sinatra,twanies/sinatra,eileencodes/sinatra,davydovanton/sinatra,blambeau/sinatra,howtolearntocode/sinatra,kumji/sinatra,ktw1222/sinatra,kyontan/sinatra,ryanshaw/sinatra,frechei/sinatra,frechei/sinatra,eileencodes/sinatra,sinatra/sinatra,nju520/sinatra,cyberid41/sinatra,JonRowe/sinatra,ABaldwinHunter/sinatra-classic,trexnix/sinatra,sethuster/sinatra,dariubs/sinatra,JonMidhir/sinatra,mwpastore/sinatra