fix for weird CmdPeriod behavior

using ctrl/cmd-. produced zomby nodes when global shortcuts were
enabled. This fix seems to have solved the issue by avoiding adding a
new CmdPeriod action any time ctrl/cmd-. is hit

Signed-off-by:  <st9fan@gmail.com>
(cherry picked from commit 23bf4a3ee34777918f47326bbbad7f521bcc18a5)
Signed-off-by: Stefan Nussbaumer <st9fan@gmail.com>