Fix: teleop jog speed uncontrollable from gui

4.7. in Todo-2.6 says: test jog speed - Tomaz T reports on emc-users 2013-10-10
or so that ja3 jogging speed is not controllable

This was my screwup while fixing another bug where the jog speed was not
limited to the AXIS maximum; this change does both by capping the jog speed
request.
rdelta: set more appropriate axis jog speed limit