Mobile Upload

[WolfDieterKattnig]

Describe the bug
First of all: Dear kiswa, thank you for your great piece of software! I really very much appreciate your work.
One problem that I have encountered is, that on my phone the button to choose a file for upload doesn't work. I assume, this is not much of an issue for others, but I'd like to use TaskBoard on my iPad and attach Photos to Tasks.
Is there a "workaround"?

To Reproduce
Steps to reproduce the behavior:

1. Go to "ViewTask" on a mobile(!) device
2. Click on "Choose File"
3. Nothing happens

Expected behavior
A file select dialog should appear just like on a desktop system.

Please complete the following information:

• OS: iOS11
• Chrom, Safari
• latest