cmd: fix shebang

[nmdnm]

Signed-off-by: vikaig vikaig99@gmail.com

Fixes these errors

$ lxc-checkconfig
Failed to execute process '/usr/bin/lxc-checkconfig'. Reason:
exec: Exec format error
The file '/usr/bin/lxc-checkconfig' is marked as an executable but could not be run by the operating system.

$ lxc-update-config
Failed to execute process '/usr/bin/lxc-update-config'. Reason:
exec: Exec format error
The file '/usr/bin/lxc-update-config' is marked as an executable but could not be run by the operating system.

[lxc-jenkins]

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[brauner]

Thanks!