wallet2: fix refresh retry when a block/tx fails to parse

It would switch to a new set of blocks and fail, getting out of sync
with the hash chain in the process

src/wallet/wallet2.cpp

@@ -2498,10 +2498,6 @@ void wallet2::refresh(bool trusted_daemon, uint64_t start_height, uint64_t & blo
         break;
       }
 
-      // switch to the new blocks from the daemon
-      blocks_start_height = next_blocks_start_height;
-      blocks = std::move(next_blocks);
-      parsed_blocks = std::move(next_parsed_blocks);
       first = false;
 
       // handle error from async fetching thread
@@ -2509,6 +2505,11 @@ void wallet2::refresh(bool trusted_daemon, uint64_t start_height, uint64_t & blo
       {
         throw std::runtime_error("proxy exception in refresh thread");
       }
+
+      // switch to the new blocks from the daemon
+      blocks_start_height = next_blocks_start_height;
+      blocks = std::move(next_blocks);
+      parsed_blocks = std::move(next_parsed_blocks);
     }
     catch (const std::exception&)
     {