don't remove the quotes from the etag

src/rebar_pkg_resource.erl

@@ -135,10 +135,10 @@ make_vsn(_, _) ->
 -spec request(rebar_hex_repos:repo(), binary(), binary(), false | binary())
              -> {ok, cached} | {ok, binary(), binary()} | error.
 request(Config, Name, Version, ETag) ->
-    Config1 = Config#{http_etag => <<"\"", ETag/binary, "\"">>},
+    Config1 = Config#{http_etag => ETag},
     try hex_repo:get_tarball(Config1, Name, Version) of
         {ok, {200, #{<<"etag">> := ETag1}, Tarball}} ->
-            {ok, Tarball, rebar_utils:to_binary(rebar_string:trim(rebar_utils:to_list(ETag1), both, [$"]))};
+            {ok, Tarball, ETag1};
         {ok, {304, _Headers, _}} ->
             {ok, cached};
         {ok, {Code, _Headers, _Body}} ->