Mayweather and Silva were due to compete on a helipad this evening. The Global Titans Fight Series event that was scheduled to take place today on the helipad of the Burj Al Arab Jumeirah hotel in Dubai has been cancelled. That event was due to feature both Floyd Mayweather Jr. and Anderson Silva in exhibition boxing matches. According to TMZ the reason behind the cancellation is the unexpected death of United Arab Emirates president Shiekh Khalifa bin Zayed Al Nahyan. After the leader’s death yesterday the country announced a three day shut down of all businesses. “Out of deepest respect…