Don't use webpack multi entry unnecessarily

[sebmarkbage]

Passing an array with a single entry is not equivalent. This causes Webpack to generate another wrapper module around the entry. This is just unnecessary overhead and bytes.

Before:

...
/***/ 10:
/***/ (function(module, __webpack_exports__, __webpack_require__) {
...
/***/ }),
/***/ 5:
/***/ (function(module, exports, __webpack_require__) {
module.exports = __webpack_require__(10);
/***/ })
},[[5,1,2]]]);

After:

...
/***/ 10:
/***/ (function(module, __webpack_exports__, __webpack_require__) {
...
/***/ })
},[[10,1,2]]]);

[ianschmitz]

Good catch. Thanks @sebmarkbage!