Scrolling with mouse wheel does not work properly in chat window

[simonschaufi]

Expected Behavior

Scrolling with the mouse wheel in the chat windows scrolls to old chat messages (always!)

Current Behavior

I haven't figured it out when scrolling works but most of the time nothing is scrolling. When I scroll up and down, the "arrow icon" to scroll down appear and disappear and when there is a picture, it looks like the pic is loaded again and again (become sharp and unsharp).
The moment I "broke out" of being stuck at the bottom i can scroll easily and load all the old history

Possible Solution

I don't even see a scrollbar...

Steps to Reproduce (for bugs)

1. click on contact to start chatting
2. scroll up to load old history

Your Environment

• Threema Web version: Version 1.0.5
• Browser name and version: SRWare Iron / Google Chrome 55
• Operating system and version: Windows 7 (but shouldn't matter)

[dbrgn]

Duplicate of #18.