update ethmagicians link

Author: Marchhill

EIPS/eip-7793.md

@@ -3,7 +3,7 @@ eip: 7793
 title: TXINDEX precompile
 description: Precompile to get index of transaction within block
 author: Marc Harvey-Hill (@Marchhill), Ahmad Bitar (@smartprogrammer93)
-discussions-to: https://ethereum-magicians.org/t/eip-7793-txindex-opcode/21513
+discussions-to: https://ethereum-magicians.org/t/eip-7793-txindex-precompile/21513
 status: Draft
 type: Standards Track
 category: Core