fix: jwt-aud config not failing when set to invalid URI (#4140)

The `jwt-aud` config was not validated when containing ':'
character according to RFC 3986. This fix validates it and
fails at startup if it is invalid.

test/io/test_cli.py

@@ -278,3 +278,15 @@ def test_schema_cache_snapshot(baseenv, key, snapshot_yaml):
         Dumper=yaml.SafeDumper if key == "dbTimezones" else ExtraNewLinesDumper,
     )
     assert formatted == snapshot_yaml
+
+
+def test_jwt_aud_config_set_to_invalid_uri(defaultenv):
+    "PostgREST should exit with an error message in output if jwt-aud config is set to an invalid URI"
+    env = {
+        **defaultenv,
+        "PGRST_JWT_AUD": "foo://%%$$^^.com",
+    }
+
+    with pytest.raises(PostgrestError):
+        dump = cli(["--dump-config"], env=env).split("\n")
+        assert "jwt-aud should be a string or a valid URI" in dump