Error when FocusGained event fires in the commandline history window

[frioux]

To repro:

1. Press q: or :<C-f>
2. Mouse in and out of window

You should get an error something like this:

Error detected while processing FocusGained Auto commands for "*":
E11: Invalid in command-line window; <CR> executes, CTRL-C quits: checktime

[wincent]

Thanks for the error report, @frioux. I've seen this before but have been too lazy to fix it. Will put up a proposed fix in a sec.