Dont fetch ahead if cbopret chain, yes it will slow it down

src/main.cpp

@@ -512,6 +512,8 @@ namespace {
         // Never fetch further than the best block we know the peer has, or more than BLOCK_DOWNLOAD_WINDOW + 1 beyond the last
         // linked block we have in common with this peer. The +1 is so we can detect stalling, namely if we would be able to
         // download that next block if the window were 1 larger.
+        if ( ASSETCHAINS_CBOPRET != 0 )
+            BLOCK_DOWNLOAD_WINDOW = 1;
         int nWindowEnd = state->pindexLastCommonBlock->GetHeight() + BLOCK_DOWNLOAD_WINDOW;
         int nMaxHeight = std::min<int>(state->pindexBestKnownBlock->GetHeight(), nWindowEnd + 1);
         NodeId waitingfor = -1;

src/main.h

@@ -111,7 +111,7 @@ static const unsigned int MAX_HEADERS_RESULTS = 160;
  *  Larger windows tolerate larger download speed differences between peer, but increase the potential
  *  degree of disordering of blocks on disk (which make reindexing and in the future perhaps pruning
  *  harder). We'll probably want to make this a per-peer adaptive value at some point. */
-static const unsigned int BLOCK_DOWNLOAD_WINDOW = 1024;
+static unsigned int BLOCK_DOWNLOAD_WINDOW = 1024;
 /** Time to wait (in seconds) between writing blocks/block index to disk. */
 static const unsigned int DATABASE_WRITE_INTERVAL = 60 * 60;
 /** Time to wait (in seconds) between flushing chainstate to disk. */