Fix options.context being not extensible

Fixes #1077

Author: szmarczak

source/core/options.ts

@@ -2521,6 +2521,5 @@ export default class Options {
 		Object.freeze(options.retry.errorCodes);
 		Object.freeze(options.retry.methods);
 		Object.freeze(options.retry.statusCodes);
-		Object.freeze(options.context);
 	}
 }

test/arguments.ts

@@ -328,6 +328,18 @@ test.failing('`context` option is enumerable', withServer, async (t, server, got
 	});
 });
 
+test('`context` option is never frozen', t => {
+	const client = got.extend({
+		context: {
+			token: 'foobar',
+		},
+	});
+
+	client.defaults.options.context.token = '1234';
+
+	t.is(client.defaults.options.context.token, '1234');
+});
+
 test('`context` option is accessible when using hooks', withServer, async (t, server) => {
 	server.get('/', echoUrl);