Christian Klein jogs onto the stage at SAP SE’s annual sales conference in a grey sweatsuit like he's taking a victory lap. And in some ways, he is. The 45-year-old chief executive officer took the helm six years ago just as the company’s sales were starting to stagnate. SAP — which makes software that runs finance, sales and other corporate functions — missed the industry’s shift to the cloud and was playing catchup. In one of his first earnings reports as CEO, Klein gave a bleak outlook and th...