build(#237): Don't implicitly enable flate2/any_impl, so that error…

… when missing a back-end is more readable

Signed-off-by: Chris Hennick <[email protected]>

Cargo.toml

@@ -70,7 +70,7 @@ chrono = ["chrono/default"]
 _deflate-any = []
 _all-features = [] # Detect when --all-features is used
 deflate = ["flate2/rust_backend", "deflate-zopfli", "deflate-flate2"]
-deflate-flate2 = ["flate2/any_impl", "_deflate-any"]
+deflate-flate2 = ["_deflate-any"]
 # DEPRECATED: previously enabled `flate2/miniz_oxide` which is equivalent to `flate2/rust_backend`
 deflate-miniz = ["deflate", "deflate-flate2"]
 deflate-zlib = ["flate2/zlib", "deflate-flate2"]