docs(dip31): update field name

dip-0031.md

@@ -56,7 +56,7 @@ system and introduced in Protocol Version `70235`.
 | protxHash | uint256 | 32 | The protxHash of the evonode being banned |
 | signedHeight | int32_t | 4 | The height at which this message was signed by the platform quorum |
 | quorumHash | uint256 | 32 | The quorumHash of the quorum which signed the message |
-| blsSignature | byte[] | 96 | The BLS signature over the message, by the quorum identified by quorumHash |
+| signature | byte[] | 96 | The BLS signature over the message, by the quorum identified by quorumHash |
 
 Note: this P2P message intentionally excludes an internal version; instead, it is versioned via the
 Protocol Version.