no more feature gate in the example

dignifiedquire · dignifiedquire · commit 04d43a03f79e · 2019-11-11T18:31:30.000+01:00
diff --git a/src/connector.rs b/src/connector.rs
@@ -25,8 +25,6 @@ use webpki::DNSNameRef;
 /// ## Example
 ///
 /// ```rust
-/// #![feature(async_await)]
-///
 /// use async_tls::TlsConnector;
 ///
 /// async_std::task::block_on(async {
