printing with svg header fails

[landryb]

Describe the bug
the printing module only prints empty white files when the template header image points at the attached SVG like this:

           items:
             - !image
               maxWidth: 550
               url: 'file://${configDir}/bando_mapstore_impression.svg'

zero related log message is found in mapstore.log, and i havent found a way to make mapfishprint more verbose (turning mapstore logging to debug doesnt yield more messages from the printing engine)

i had to convert my svg to png to get printing working again, while the same svg header worked fine with 2023.02.

Screenshots

[landryb]

fwiw the svg file has the same height/width as the default png file (print_header.png) - i guess that's a regression from #714, that afaict updated the print-lib module from geosolutions-2.2.0 to 2.3.1 ?