This function tried to move the client to its new screen based on
shifting around its current geometry. However, it assumed that the
client was actually visible on its current screen, which is not always
the case.
Fix this by just forcing the client into its new screen if our moving
approach does not work.
This also reverts commit d5e365804c which
is no longer necessary. This commit only hid the issue (partly).
Fixes: https://github.com/awesomeWM/awesome/issues/318
Signed-off-by: Uli Schlachter <psychon@znc.in>