Allow setting inlineImageLimit value to 0

`0` being falsy, the previous default parameter logic was overwriting the value. This disallowed user to disable image inlining.

index.js

@@ -2,24 +2,23 @@ module.exports = (nextConfig = {}) => {
  return Object.assign({}, nextConfig, {
  webpack(config, options) {
  const { isServer } = options;
+ nextConfig = Object.assign({ inlineImageLimit: 8192, assetPrefix: "" }, nextConfig);
+
  if (!options.defaultLoaders) {
  throw new Error(
  'This plugin is not compatible with Next.js versions below 5.0.0 https://err.sh/next-plugins/upgrade'
  )
  }
 
- const assetPrefix = nextConfig.assetPrefix || "";
- const limit = nextConfig.inlineImageLimit || 8192;
-
  config.module.rules.push({
  test: /\.(jpe?g|png|svg|gif|ico)$/,
  use: [
  {
  loader: "url-loader",
  options: {
- limit,
+ limit: nextConfig.inlineImageLimit,
  fallback: "file-loader",
- publicPath: `${assetPrefix}/_next/static/images/`,
+ publicPath: `${nextConfig.assetPrefix}/_next/static/images/`,
  outputPath: `${isServer ? "../" : ""}static/images/`,
  name: "[name]-[hash].[ext]"
  }