Disable proof generation when testmode is enabled in async SendMany operation.

src/wallet/asyncrpcoperation_sendmany.cpp

@@ -838,7 +838,8 @@ Object AsyncRPCOperation_sendmany::perform_joinsplit(
             {info.vjsin[0], info.vjsin[1]},
             {info.vjsout[0], info.vjsout[1]},
             info.vpub_old,
-            info.vpub_new);
+            info.vpub_new,
+            !this->testmode);
 
     if (!(jsdesc.Verify(*zcashParams_, joinSplitPubKey_))) {
         throw std::runtime_error("error verifying joinsplit");

src/wallet/asyncrpcoperation_sendmany.h

@@ -54,7 +54,7 @@ public:
     
     virtual void main();
 
-    bool testmode = false;  // Set this to true to disable sending transactions to the network
+    bool testmode = false;  // Set to true to disable sending txs and generating proofs
 
 private:
     friend class TEST_FRIEND_AsyncRPCOperation_sendmany;    // class for unit testing