fix: allow unicode filenames

[hwbllmnn]

GeoServer won't start if you have e.g. a style with an umlaut in the filename. With this PR this is fixed.

[buehner]

Thank you! Is there a reason to not add this to the previous stage where apt is already used?

If not: Could you give it a try by applying the change there?

[hwbllmnn]

Thank you! Is there a reason to not add this to the previous stage where apt is already used?

If not: Could you give it a try by applying the change there?

Yes, the change needs to be available at runtime, so adding the package to a previous stage doesn't help.

[hwbllmnn]

Thank you! Is there a reason to not add this to the previous stage where apt is already used? If not: Could you give it a try by applying the change there?

Yes, the change needs to be available at runtime, so adding the package to a previous stage doesn't help.

Alright, I didn't realize that the actual image starts from the first stage, I moved the apt stuff there like you suggested.