Fix bug: nCachedBlockHeight was not updated on start (#1673)

in submodules if no new blocks were received since previous shutdown.
This was breaking some sync logic e.g. for payment votes.

src/dsnotificationinterface.cpp

@@ -55,7 +55,7 @@ void CDSNotificationInterface::UpdatedBlockTip(const CBlockIndex *pindexNew, con
         }
     }
 
-    if (fInitialDownload || !masternodeSync.IsBlockchainSynced())
+    if (fInitialDownload)
         return;
 
     mnodeman.UpdatedBlockTip(pindexNew);