Log if we have no zsweepaddress or an invalid zsweepaddress

src/wallet/asyncrpcoperation_sweep.cpp

@@ -103,12 +103,14 @@ bool AsyncRPCOperation_sweep::main_impl() {
                     }
                 }
             } else {
+                LogPrintf("%s: No zsweepaddress configured, exiting\n", opid);
                 return false;
             }
         } else {
             if (boost::get<libzcash::SaplingPaymentAddress>(&rpcSweepAddress) != nullptr) {
                 sweepAddress = boost::get<libzcash::SaplingPaymentAddress>(rpcSweepAddress);
             } else {
+                LogPrintf("%s: Invalid zsweepaddress, exiting\n", opid);
                 return false;
             }
         }