fix(cordova-plugin-inappbrowser): remove not needed type

types/cordova-plugin-inappbrowser/index.d.ts

@@ -6,7 +6,6 @@
 // Copyright (c) Microsoft Open Technologies Inc
 // Licensed under the MIT license.
 // TypeScript Version: 2.3
-type target = "_self" | "_blank" | "_system";
 type channel = "loadstart" | "loadstop" | "loaderror" | "exit";
 
 interface Window {
@@ -18,7 +17,7 @@ interface Window {
      *                 The options string must not contain any blank space, and each feature's
      *                 name/value pairs must be separated by a comma. Feature names are case insensitive.
      */
-    open(url: string, target?: target | string, options?: string, replace?: boolean): InAppBrowser;
+    open(url: string, target?: string, options?: string, replace?: boolean): InAppBrowser;
 }
 
 /**