Grey out bogus tens column buttons in LItems tab

[Asuna Yuuki Nagato]

Steps to recreate:

• Quest->Init Data->LItems
• Click 500 button
• Click 90 button
• Observe only rows 510 and 512 are displayed

There are only 512 rows of MCBTKey, so if we greyed out the 20-90 tens buttons when the 500 button is selected, that will reduce confusion among people clicking them and suprised that they do nothing.

[Asuna Yuuki Nagato]

This tab is created by InitDataDialog::view() in init_data.cpp