runtime-rs: Remove redundant empty line

While running `cargo fmt -- --check` in `src/runtime-rs` directory, it
errors out and suggesting these is an redundant empty line, which
prevents `make check` of `runtime-rs` component from passing.

Remove redundant empty line to fix this.

Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>

src/runtime-rs/crates/runtimes/src/lib.rs

@@ -4,7 +4,6 @@
 // SPDX-License-Identifier: Apache-2.0
 //
 
-
 #[macro_use(lazy_static)]
 extern crate lazy_static;