[0.13.16] Electric network info panel doesn't auto resize

[Boogieman14]

A very minor cosmetic thingy that I just noticed:

1. allow the electric network to drain (ie: accumulators are empty during the night) (http://prntscr.com/c72t1h)
2. open the electric network info panel so that it shows Satisfaction/production/charge at 0, consumers and producers panes are empty. The window will be vertically centered
3. wait for daytime, consumption and production panels are filled. The top of the window doesn't move, the bottom extends to below the lower edge of the screen (http://prntscr.com/c72tyg)

[Loewchen]

Duplicate of: viewtopic.php?f=23&t=30685