GLOG dependency remained in the atomic CMakeLists.txt

glog was removed from the source of atomic example but its dependency remained in CMakeLists.txt.
Fix:
```sh
sed -i -e '/GLOG/d' -e '/glog/,+1 d' CMakeLists.txt
```

A same pr: https://github.com/baidu/braft/pull/51

Open the atomic example's CMakeLists.txt and inspect the remaining GLOG and glog dependency entries. Remove the stale dependency references described in the issue, then verify that the atomic example's CMake configuration still succeeds. The linked pull request should be checked because the issue identifies the work as already proposed there.

Written by the indexing model from the issue text.