[glib-networking] (7 commits) ...meson: error out if no TLS backends are enabled

[Michael Catanzaro <mcatanzaro src gnome org>]

Summary of changes:

  a55f550... meson: required is true by default (*)
  14a3138... Make gnutls optional (*)
  18dbdb6... Add myself to doap file (*)
  8629f3d... meson: use the new feature option type for options (*)
  f59667d... tests: it is fine to pass a not-found target to the deps (*)
  cb662e2... meson: do not build pkcs11 if gnutls is not enabled (*)
  c2783e3... meson: error out if no TLS backends are enabled (*)

(*) This commit already existed in another branch; no separate mail sent