Hello Everyone.
I found the way to eliminate that pesky blank space. (I search through internet but didn’t find any answer for this. So I decided to make a post.)
Here are a few steps:
1. For PC:Go to the Koreader folder on your device, open the defaults.lua and change DCREREADER_CONFIG_B_MARGIN_SIZES_SMALL to -15.
2. For Ereader:Summon the Main Menu, select the bottom tab with margin settings and set the bottom margin default value to -15 by pressing on the leftmost box.
I hope it will help someone.
Is there another way to get rid of it?