Hotfix for Demo Update 3

Hey,

I had a few new crashes reported to my trello. Sorry for the inconvenience. The update should fix most of the new issue. I will have a close eye on new problems and fix them right aways.

• Fixed a crash for mortar cannons trying to attack an enemy when there were 0 enemies lin the attacklist.
  
• Fixed a rare crash in send squads UI due to a timing issue.
  
• Fixed a rare crash when showing health bars, due to a timing issue.
  
• Fixed type names for buildslots
  
• Build slots construction now also depends on magic school levels.
  

Thanks for your patience.