NEP-Y: extend list of verifyproof return error codes

Proof verification is relevant only for the nodes that store not only
the latest chain state.

Signed-off-by: Anna Shaleva <[email protected]>

Author: AnnaShaleva

nep-Y.mediawiki

@@ -298,7 +298,7 @@ Neo-specific codes are documented here, generic JSON-RPC errors like -32602 or
 |-
 | validateaddress     ||
 |-
-| verifyproof         || -607
+| verifyproof         || -606, -607
 |}