Reformat rust code using 1.40 rustfmt and fail build if rustfmt fails (#2339)

diff --git a/lib/rs/src/protocol/multiplexed.rs b/lib/rs/src/protocol/multiplexed.rs
index 83498fb..697b7e6 100644
--- a/lib/rs/src/protocol/multiplexed.rs
+++ b/lib/rs/src/protocol/multiplexed.rs
@@ -191,7 +191,9 @@
 #[cfg(test)]
 mod tests {
 
-    use crate::protocol::{TBinaryOutputProtocol, TMessageIdentifier, TMessageType, TOutputProtocol};
+    use crate::protocol::{
+        TBinaryOutputProtocol, TMessageIdentifier, TMessageType, TOutputProtocol,
+    };
     use crate::transport::{TBufferChannel, TIoChannel, WriteHalf};
 
     use super::*;