Fix a memory leak

src/core/lib/compression/stream_compression_gzip.cc

@@ -60,7 +60,7 @@ static bool gzip_flate(grpc_stream_compression_context_gzip* ctx,
       if (r < 0 && r != Z_BUF_ERROR) {
         gpr_log(GPR_ERROR, "zlib error (%d)", r);
         grpc_slice_unref_internal(slice_out);
-
+        grpc_slice_unref_internal(slice);
         return false;
       } else if (r == Z_STREAM_END && ctx->flate == inflate) {
         eoc = true;