WENDELL ROELF and TANISHA HEIBERG THE prospect of chasing cocktails and contacts in the shadow of Table Mountain draws executives and officials from around the world to Cape Town each year for Africa's biggest mining conference. But this year the Investing in African Mining Indaba is online only and has been cut to two days rather than four as a second wave of the COVID-19 pandemic sweeps South Africa. For the mining industry, it means not only foregoing Cape Town's famed wines, vistas and sun but also a key deal-making and networking opportunity - not to mention the blow to…