When editing adive in Subsurface-mobile we can only handle one buddy
due to the limitations of the combobox. To prevent loss of data when editing
a dive with more than one buddy we display "Multiple Buddies" in the buddy
field. This creates a special case where no changes are written to the buddy field
unless the user changes buddy for that dive.
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>