Changed the default to overcome the changes in:
5018fdacbeb0807fc255f83049044b89323eea55
This commit exposed a bug because the Ender-2 was using a MINIPANEL lcd
and getting default values that were too low, so the text was too weak.
However, the panel should be MKS_MINI_12864, since it
explicitly sets the correct contrast without relying in the defaults.
be37c38aa2