Update AWS SDK to 1.12.7

Fix #54032

vendor/github.com/aws/aws-sdk-go/aws/url.go

@@ -0,0 +1,12 @@
+// +build go1.8
+
+package aws
+
+import "net/url"
+
+// URLHostname will extract the Hostname without port from the URL value.
+//
+// Wrapper of net/url#URL.Hostname for backwards Go version compatibility.
+func URLHostname(url *url.URL) string {
+	return url.Hostname()
+}