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

This closes #1851
diff --git a/lib/rs/src/server/threaded.rs b/lib/rs/src/server/threaded.rs
index e15a25a..8f8c082 100644
--- a/lib/rs/src/server/threaded.rs
+++ b/lib/rs/src/server/threaded.rs
@@ -194,7 +194,7 @@
     fn new_protocols_for_connection(
         &mut self,
         stream: TcpStream,
-    ) -> ::Result<(Box<TInputProtocol + Send>, Box<TOutputProtocol + Send>)> {
+    ) -> ::Result<(Box<dyn TInputProtocol + Send>, Box<dyn TOutputProtocol + Send>)> {
         // create the shared tcp stream
         let channel = TTcpChannel::with_stream(stream);
 
@@ -216,8 +216,8 @@
 
 fn handle_incoming_connection<PRC>(
     processor: Arc<PRC>,
-    i_prot: Box<TInputProtocol>,
-    o_prot: Box<TOutputProtocol>,
+    i_prot: Box<dyn TInputProtocol>,
+    o_prot: Box<dyn TOutputProtocol>,
 ) where
     PRC: TProcessor,
 {