update channel.rs, remove useless variables.

Signed-off-by: DogDu <[email protected]>

Author: Dog-Du

src/channel.rs

@@ -315,29 +315,6 @@ impl ChannelBuilder {
         self
     }
 
-    /// Set default gzip compression level.
-    #[cfg(feature = "nightly")]
-    pub fn default_gzip_compression_level(mut self, level: usize) -> ChannelBuilder {
-        self.options.insert(
-            Cow::Borrowed(grpcio_sys::GRPC_ARG_GZIP_COMPRESSION_LEVEL),
-            Options::Integer(level as i32),
-        );
-        self
-    }
-
-    /// Set default grpc min message size to compression.
-    #[cfg(feature = "nightly")]
-    pub fn default_grpc_min_message_size_to_compress(
-        mut self,
-        lower_bound: usize,
-    ) -> ChannelBuilder {
-        self.options.insert(
-            Cow::Borrowed(grpcio_sys::GRPC_ARG_MIN_MESSAGE_SIZE_TO_COMPRESS),
-            Options::Integer(lower_bound as i32),
-        );
-        self
-    }
-
     /// Set default compression level for the channel.
     pub fn default_compression_level(mut self, level: CompressionLevel) -> ChannelBuilder {
         self.options.insert(