Ignore Error description deprecation warnings

This commit allows warnings on the description() impl for Error types.
description is soft deprecated in 1.41.0, to use the Display impl or to_string() instead,
but the warning message seems to be just compile noise for now.

Author: russcam

api_generator/src/rest_spec/parallel_downloading.rs

@@ -134,6 +134,7 @@ impl std::fmt::Display for DownloadSpecsErrors {
 }
 
 impl StdError for DownloadSpecsErrors {
+    #[allow(warnings)]
     fn description(&self) -> &str {
         match self {
             DownloadSpecsErrors::IoErr(err) => err.description(),

elasticsearch/src/error.rs

@@ -73,6 +73,7 @@ impl From<BuildError> for Error {
 }
 
 impl error::Error for Error {
+    #[allow(warnings)]
     fn description(&self) -> &str {
         match *self {
             Error::Build(ref err) => err.description(),

elasticsearch/src/http/transport.rs

@@ -42,6 +42,7 @@ impl From<reqwest::Error> for BuildError {
 }
 
 impl error::Error for BuildError {
+    #[allow(warnings)]
     fn description(&self) -> &str {
         match *self {
             BuildError::Io(ref err) => err.description(),