The LXC built-in exec driver has been deprecated in 1.8 and
further removed in 1.10, yet in deprecated.md it still shows:
```
Target For Removal In Release: v1.10
```
This fix changes the above to `Removed In Release:`.
In addition, lxc-conf flag and API fields have already been
removed in 1.10 as well so the related description has also been
updated in this fix.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
Upstream-commit: 14b82790df
Component: cli
52be616162