fix engrish

Author: zimbatm

rfcs/0000-rfc-process.md

@@ -84,7 +84,7 @@ wider community review. And the review process happens.
 After the review process has settled a decision is taken by community vote,
 with @edolstra as a BDFL that can override any decision.
 
-Whomever merges the RFC should do the following:
+Whoever merges the RFC should do the following:
 
 * Create a corresponding issue on the appropriate repo (NixOS/Nix,
   NixOS/nixpkgs, ...).