Delete content-encoding header after decompression

lib/req/steps.ex

@@ -825,10 +825,18 @@ defmodule Req.Steps do
 
       iex> response = Req.get!("https://httpbin.org/gzip")
       iex> List.keyfind(response.headers, "content-encoding", 0)
-      {"content-encoding", "gzip"}
+      nil
       iex> response.body["gzipped"]
       true
 
+      iex> response = Req.get!("https://httpbin.org/gzip", raw: true)
+      iex> List.keyfind(response.headers, "content-encoding", 0)
+      {"content-encoding", "gzip"}
+      iex> response.body
+      <<31, 139, 8, 0, 152, 130, 144, 100, 2, 255, 61, 143, 61, 111, 195, 32, 16, 134,
+        119, 255, 10, 196, 108, 168, 49, 254, 8, 145, 58, 120, 136, 210, 174, 85, 42,
+        117, 117, 224, 130, 145, 26, 112, 240, 117, 113, 148, 255, 94, 112, 164, ...>>
+
   If the [brotli] package is installed, Brotli is also supported:
 
       Mix.install([
@@ -857,7 +865,16 @@ defmodule Req.Steps do
 
   def decompress_body({request, response}) do
     compression_algorithms = get_content_encoding_header(response.headers)
-    {request, update_in(response.body, &decompress_body(&1, compression_algorithms))}
+
+    response =
+      Req.Response.new(
+        status: response.status,
+        headers: List.keydelete(response.headers, "content-encoding", 0),
+        body: decompress_body(response.body, compression_algorithms),
+        private: response.private
+      )
+
+    {request, response}
   end
 
   defp decompress_body(body, algorithms) do