Revert "Revert init hooks not being called on empty options"

This reverts commit a398e36.

Author: szmarczak

source/core/options.ts

@@ -803,7 +803,7 @@ export default class Options {
 				}
 			} else {
 				try {
-					this.merge(options ?? {});
+					this.merge(options);
 				} finally {
 					if (options?.url !== undefined) {
 						if (input === undefined) {

test/create.ts

@@ -233,7 +233,7 @@ test('does not include the `request` option in normalized `http` options', withS
 });
 
 test('should pass an options object into an initialization hook after .extend', withServer, async (t, server, got) => {
-	t.plan(2);
+	t.plan(1);
 
 	server.get('/', echoHeaders);