setter nit

Author: jooohhn

src/amplitude-client.js

@@ -1849,7 +1849,7 @@ AmplitudeClient.prototype.__VERSION__ = function getVersion() {
  * @param {string} version - Custom library version
  */
 AmplitudeClient.prototype.setLibrary = function setLibrary(name, version) {
-  return (this.options.library = { name, version });
+  this.options.library = { name: name, version: version };
 };
 
 /**