@onur-baran also the fav icon has to do with browser cache and memory etc, which is out of control of NodeBB. If you’ve determined it is part of NodeBB, report it.
Installing an older NodeBB Version
How do you install this version of Nodebb instead of the current one. The Background looks like this:
We can help more with a detailed example BUT....
Let's say you want the latest in the 0.6.x family. you would do:
git fetch; git checkout v0.6.x; git pull; ./nodebb setup
Or for a fresh installation:
git clone -b v0.6.x https://github.com/NodeBB/NodeBB.git nodebb