Update btp_extension.md, removing empty column
@@ -622,11 +622,11 @@ SHA3Sum256([VoteMessage](#votemessage)).
> B_LIST of followings
-| Name | Field | Type | Description |
-|:-----|:--------|:---------------------|:-------------------------------|
-| | Addr | B_ADDRESS | SCORE producing this event log |
-| | Indexed | B_LIST of B_BYTES(N) | Indexed data. |
-| | Data | B_LIST of B_BYTES(N) | Remaining data. |
+| Field | Type | Description |
+|:--------|:---------------------|:-------------------------------|
+| Addr | B_ADDRESS | SCORE producing this event log |
+| Indexed | B_LIST of B_BYTES(N) | Indexed data. |
+| Data | B_LIST of B_BYTES(N) | Remaining data. |
### Merkle Patricia Trie
