Stop throwing error when no callback exists
Stop throwing error when no callback exists

BranchMetrics/Smart-App-Banner-Deep-Linking-Web-SDK,BranchMetrics/Smart-App-Banner-Deep-Linking-Web-SDK,BranchMetrics/Smart-App-Banner-Deep-Linking-Web-SDK,BranchMetrics/Smart-App-Banner-Deep-Linking-Web-SDK