clearer error when plugin is missing

src/utils/errors.ts

@@ -29,7 +29,6 @@ const errors = {
 	18(plugin: string) {
 		return `The plugin for '${plugin}' has not been loaded into Immer. To enable the plugin, import and call \`enable${plugin}()\` when initializing your application.`
 	},
-	19: "plugin not loaded",
 	20: "Cannot use proxies if Proxy, Proxy.revocable or Reflect are not available",
 	21(thing: string) {
 		return `produce can only be called on things that are draftable: plain objects, arrays, Map, Set or classes that are marked with '[immerable]: true'. Got '${thing}'`

src/utils/plugins.ts

@@ -52,7 +52,7 @@ export function getPlugin<K extends keyof Plugins>(
 ): Exclude<Plugins[K], undefined> {
 	const plugin = plugins[pluginKey]
 	if (!plugin) {
-		die(__DEV__ ? 18 : 19, pluginKey)
+		die(18, pluginKey)
 	}
 	// @ts-ignore
 	return plugin