clear out situation when one tries to start a DB without a block

storage/src/lib.rs

@@ -103,9 +103,8 @@ impl RocksDBIO {
 
             Ok(dbio)
         } else {
-            warn!("Starting db in unset mode, will have to set starting block manually");
-
-            Ok(dbio)
+            // Here we are trying to start a DB without a block, one should not do it.
+            unreachable!()
         }
     }