Update file info after reload command

[joelim-work]

Fixes #1087

To reproduce the issue:

1. Open lf and select a file
2. Start a new terminal, and use chmod to change the file permissions
3. Go back to lf and run the reload command

The current behaviour is that although reload does load the new file info (asynchronously), it isn't displayed because of the following condition:

lf/app.go

Lines 417 to 419 in 3fc1db5

	if app.ui.msg == "" {
	app.ui.loadFileInfo(app.nav)
	}

It turns out that this code was added to display the file info when starting up, see #994. So just after the reload command, I clear app.ui.msg to create a similar situation.

I also considered just removing the if app.ui.msg == "" condition during the asynchronous reload, but that could cause issues like clearing out error messages at unexpected times.

[gokcehan]

@joelim-work Looks good, thanks for the patch.