enable hyper's http2 feature

Author: wg

rusoto/core/Cargo.toml

@@ -27,7 +27,7 @@ bytes = "1.0"
 crc32fast = "1.2"
 futures = "0.3"
 http = "0.2"
-hyper = { version = "0.14", features = ["client", "http1", "tcp"] }
+hyper = { version = "0.14", features = ["client", "http1", "http2", "tcp"] }
 hyper-rustls = { version = "0.22", optional = true }
 hyper-tls = { version = "0.5.0", optional = true }
 lazy_static = "1.4"