simplewallet: perform trivial error checks before password prompt

src/simplewallet/simplewallet.cpp

@@ -4715,8 +4715,6 @@ bool simple_wallet::transfer_main(int transfer_type, const std::vector<std::stri
   if (!try_connect_to_daemon())
     return true;
 
-  SCOPED_WALLET_UNLOCK();
-
   std::vector<std::string> local_args = args_;
 
   std::set<uint32_t> subaddr_indices;
@@ -4936,6 +4934,8 @@ bool simple_wallet::transfer_main(int transfer_type, const std::vector<std::stri
      }
   }
 
+  SCOPED_WALLET_UNLOCK();
+
   try
   {
     // figure out what tx will be necessary