Fix key bindings in patch when changing the old or new version

We need to reset the current row when rendering the table again,
otherwise we might be off the table and not know it if there are
a lower number of lines in the new display.

Also, don't call display() again to change the view, only once
is sufficient.

Bug: GERRIT-188
Signed-off-by: Shawn O. Pearce <sop@google.com>
2 files changed