Add log output during initial header sync

Author: jonasschnelli

src/validation.cpp

@@ -3327,6 +3327,12 @@ bool ProcessNewBlockHeaders(const std::vector<CBlockHeader>& headers, CValidatio
         }
     }
     NotifyHeaderTip();
+    {
+        LOCK(cs_main);
+        if (::ChainstateActive().IsInitialBlockDownload() && ppindex && *ppindex) {
+            LogPrintf("Synchronizing blockheaders, height: %d (~%.2f%%)\n", (*ppindex)->nHeight, 100.0/((*ppindex)->nHeight+(GetAdjustedTime() - (*ppindex)->GetBlockTime()) / Params().GetConsensus().nPowTargetSpacing) * (*ppindex)->nHeight);
+        }
+    }
     return true;
 }