Motivation for this change

Sometime while I was fixing these armv7l-linux modules, configuration-common.nix was re-organized and the author dropped the dontHaddock that used to be there on swagger2. I didn't notice until after the armv7l-linux dontCheck for swagger2 was applied.

Anyway, dontHaddock is still needed for that package on armv7l-linux.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option build-use-sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Fits CONTRIBUTING.md.