The old speed 50mm/s is too high and cause some print quality problems.
Also change the display of overhang speeds to better adhere to the code.
jira: STUDIO-9641
Change-Id: I6efa981db5bf88a9cf5bb70abb443cdfa1783025
(cherry picked from commit 979fefffd528ab1fb4e670fd88f716a3aed2e6f2)