Raise KeyError when key not found

nimbus/db/backends/sqlite_backend.nim

@@ -72,8 +72,6 @@ proc get*(db: ChainDB, key: openarray[byte]): seq[byte] =
       resSeq   = newSeq[byte](resLen)
     copyMem(resSeq.baseAddr, resStart, resLen)
     return resSeq
-  of SQLITE_DONE:
-    return @[]
   else: raiseKeySearchError(key)
 
 proc put*(db: ChainDB, key, value: openarray[byte]) =

nimbus/db/storage_types.nim

@@ -73,7 +73,7 @@ template raiseKeyWriteError*(key: auto) =
   raise newException(StorageError, "failed to write key " & $key)
 
 template raiseKeySearchError*(key: auto) =
-  raise newException(StorageError, "failure during search for key " & $key)
+  raise newException(KeyError, "failure during search for key " & $key)
 
 template raiseKeyDeletionError*(key: auto) =
   raise newException(StorageError, "failure to delete key " & $key)