Bug 35014: Only set time for enable-time flatpickr

Bug 35014: Only set time for enable-time flatpickr

This patch adds a check to the onChange function such that we only
attempt to set the default time on change for time enabled flatpickrs
when the date is entered manually.

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
(cherry picked from commit 5b25b26f70c21c609793f10706c04c9dbce4a5ad)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>