Update it_IT.po
Update it_IT.po

Distinguished the phrases about the footer and sidebar containers, also corrected the language property plus other details.
linuxbastard/FoundationPress,zeppytoh/cruorgsg-fp,randmanrjr/FoundationPress-randman,olefredrik/FoundationPress,bellatl/FoundationPress,randmanrjr/FoundationPress-randman,davenaylor/FoundationPress,colin-marshall/FoundationPress,bellatl/FoundationPress,davenaylor/FoundationPress,olefredrik/FoundationPress,zeppytoh/cruorgsg-fp,colin-marshall/FoundationPress,linuxbastard/FoundationPress