THRIFT-5042 Fix failing tests
Client: Rust
Patch: Marcin Pajkowski

This closes #1958
diff --git a/lib/rs/src/server/mod.rs b/lib/rs/src/server/mod.rs
index b719d1b..f24c113 100644
--- a/lib/rs/src/server/mod.rs
+++ b/lib/rs/src/server/mod.rs
@@ -56,7 +56,7 @@
 ///
 /// // `TProcessor` implementation for `SimpleService`
 /// impl TProcessor for SimpleServiceSyncProcessor {
-///     fn process(&self, i: &mut TInputProtocol, o: &mut TOutputProtocol) -> thrift::Result<()> {
+///     fn process(&self, i: &mut dyn TInputProtocol, o: &mut dyn TOutputProtocol) -> thrift::Result<()> {
 ///         unimplemented!();
 ///     }
 /// }