Create Reservation not possible

[Steffeng5]

After updating from 2.7.* to 2.8.5.3 it is not possible to create reservations anymore.
WebInspector shows a parsing error:

reservation.php is rendered with a warning of a pdf library:

this results in bad html where it is not possible to click the "Create" Button to create the reservation

[Steffeng5]

This can be hotfixed by changing tpl/reservation/pdf.tpl by checking 2 variables if they are an array:
126: {if $ShowReservationDetails && is_array($Accessories) && $Accessories|count > 0}

262: {if is_array($Attachments) && $Attachments|count > 0}

Not sure if this is the true fix, but it helps to hide the warning appearing in the DOM

[Steffeng5]

This is a duplicate of #40 : Can you create a 2.8.5.4 with this PR?

[effgarces]

Could you check if the same problem occurs using the current pdf.tpl in the develop branch?

[Steffeng5]

See above :) It is a duplicate of #40