Maybe this problem is solved but for future reference, I will post these two options:

- Push the original `build.prop` via ADB when on TWRP
  1. Plug the device into your PC
  2. Open a CMD or a terminal (depends on your OS)
  3. Write this commands
     ```
     adb kill-server
     adb root
     adb remount
     adb push original-build.prop /system/build.prop
     ```
 
Or

- Grab the current `build.prop`, edit the density, and then push it back
  1. Grab it by using `adb pull /system/build.prop /path/to/build.prop`
  2. Edit the `build.prop`
  3. Then push it back 
     ```
     adb kill-server
     adb root
     adb remount
     adb push edited-build.prop /system/build.prop
     ```