Removed redundant async request info

README.md

@@ -1,4 +1,4 @@
-libxdr is a library that implements a cross-browser (postMessage-supporting browsers only) cross-domain request constructor, `XDR`, using [pmxdr][1]. It's API is identical to the [XMLHttpRequest API][2] so you can drop it into existing code without making any changes other than replacing `XMLHttpRequest` with `XHR`. It also supports IE8's XDomainRequest API (eg. `onload`). Please note that a page on a website being requested must, in addition serving to the appropriate [HTTP access control][3] header(s), also have a [pmxdr host][4] located at **/pmxdr/api** (not just the script data, but HTML using the script) on the website. libxdr *does not* support synchronous requests. The `isAsynchronous` (third) argument in the open method is optional due to there being only one legal value, `true`.
+libxdr is a library that implements a cross-browser (postMessage-supporting browsers only) cross-domain request constructor, `XDR`, using [pmxdr][1]. It's API is identical to the [XMLHttpRequest API][2] so you can drop it into existing code without making any changes other than replacing `XMLHttpRequest` with `XHR`. It also supports IE8's XDomainRequest API (eg. `onload`). Please note that a page on a website being requested must, in addition serving to the appropriate [HTTP access control][3] header(s), also have a [pmxdr host][4] located at **/pmxdr/api** (not just the script data, but HTML using the script) on the website. libxdr *does not* support synchronous requests.
 
 Every browser compatible with pmxdr is compatible with libxdr. See the [supported browsers list][5] for more info. libxdr requires that pmxdr be loaded before libxdr is loaded.