Revert "syncthing: pin to go 1.14"
Revert "syncthing: pin to go 1.14"

This reverts commit 384e56bbaac9938ede50fa45989a8f594ebf293f.

Fixed in the 1.9.0 release.
https://github.com/syncthing/syncthing/releases/tag/v1.9.0

NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs