Update vendor

vendor/github.com/valyala/fasthttp/uri_windows.go

@@ -0,0 +1,12 @@
+// +build windows
+
+package fasthttp
+
+func addLeadingSlash(dst, src []byte) []byte {
+	// zero length and "C:/" case
+	if len(src) == 0 || (len(src) > 2 && src[1] != ':') {
+		dst = append(dst, '/')
+	}
+
+	return dst
+}