THRIFT-4960 bare trait (dyn) warnings
Client: Rust
Patch: Danny Browning

This closes #1851
diff --git a/lib/rs/src/protocol/stored.rs b/lib/rs/src/protocol/stored.rs
index 4fe465f..faa5128 100644
--- a/lib/rs/src/protocol/stored.rs
+++ b/lib/rs/src/protocol/stored.rs
@@ -79,7 +79,7 @@
 /// ```
 // FIXME: implement Debug
 pub struct TStoredInputProtocol<'a> {
-    inner: &'a mut TInputProtocol,
+    inner: &'a mut dyn TInputProtocol,
     message_ident: Option<TMessageIdentifier>,
 }
 
@@ -90,7 +90,7 @@
     /// with service name stripped - that will be passed to
     /// `wrapped.read_message_begin(...)`.
     pub fn new(
-        wrapped: &mut TInputProtocol,
+        wrapped: &mut dyn TInputProtocol,
         message_ident: TMessageIdentifier,
     ) -> TStoredInputProtocol {
         TStoredInputProtocol {