ocserv: add otp support

Fixes:

ocserv[225874]: unknown option 'otp'

+2
+2
pkgs/by-name/oc/ocserv/package.nix
··· 18 ronn, 19 pam, 20 libxcrypt, 21 }: 22 23 stdenv.mkDerivation (finalAttrs: { ··· 50 lz4 51 pam 52 libxcrypt 53 ]; 54 55 meta = {
··· 18 ronn, 19 pam, 20 libxcrypt, 21 + oath-toolkit, 22 }: 23 24 stdenv.mkDerivation (finalAttrs: { ··· 51 lz4 52 pam 53 libxcrypt 54 + oath-toolkit 55 ]; 56 57 meta = {