working default typescript client

Author: matryer

otohttp/templates/client.ts.plush

@@ -27,7 +27,9 @@ export class Client {
 		const headers: HeadersInit = new Headers();
 		headers.set('Accept', 'application/json');
 		headers.set('Content-Type', 'application/json');
-		await this.client.headers(headers);
+		if (this.client.headers) {
+			await this.client.headers(headers);
+		}
 		const response = await fetch(this.client.basepath + '<%= service.Name %>.<%= method.Name %>', {
 			method: 'POST',
 			headers: headers,