Fixing the instance boot source

An extra comma in the update_launch_source_displayed_fields
brakes the launch instance workflow when the option selected
is "Boot from image (creates new volume)"

Change-Id: I0f02354c8f274990fa5a7e4e2a92007513339f8a
Closes-Bug: #1333484
Imported Translations from Transifex

Change-Id: I50adf604237ce0c41c92eb1d082ce3a25d397b20
Merge "Fixing the instance boot source"