An Etymological Dictionary of the German Language/Wirt
Wirt, m., ‘host, landlord,’ from MidHG. and OHG. wirt, m., ‘husband, head of the house, sovereign of a country, host, guest, landlord (of an inn, &c.)’; comp. OSax. wërd, ‘husband, master of the house,’ Du. waard, Goth. waírdus, ‘host.’ No connection with Lat. vir, ‘man’ (for Teut. wër, see Werwolf, Welt, and Wergeld), is possible, and it can hardly be related to warten.