Upgrade rust/crates/regex to 1.4.1

Test: make
Change-Id: Ie12506e8c765f9dd8043cd61b0c77bebd887302e
diff --git a/src/re_trait.rs b/src/re_trait.rs
index b56804e..d14a9f7 100644
--- a/src/re_trait.rs
+++ b/src/re_trait.rs
@@ -51,6 +51,7 @@
 /// Positions are byte indices in terms of the original string matched.
 ///
 /// `'c` is the lifetime of the captures.
+#[derive(Clone)]
 pub struct SubCapturesPosIter<'c> {
     idx: usize,
     locs: &'c Locations,