Ensure logfile permissions are maintained after rotation (#7246)

Update our `logroller` dependency to the new version which supports permission control. See -> https://github.com/trayvonpan/logroller/pull/6

lcli/src/main.rs

@@ -675,6 +675,7 @@ fn run<E: EthSpec>(env_builder: EnvironmentBuilder<E>, matches: &ArgMatches) ->
                     extra_info: false,
                 },
                 "",
+                0o600,
             );
 
     let env = env_builder