Change two APP-6 icons

[binaryspica]

• Fix Anti-Tank type that the point is hit the top. This closes Anti-tank mark of the formation icon is not correct #462.

Former;

Now;

• Duplicate 'Mechanized' Adjustment to make the correct 'Cannon' adjustment; the current 'Mechanized.png' is actually Cannon icon(mechanized is combine of tank and infantry). I do not know how to delete the file or rename it, but if possible simply rename or delete that Mechanized.png would helps.