Commander death bug

[Bla]

A bug that blocked entire gameplay. Nothing was working.
Steps

1. Select commander upgrade which overrides other upgrade
2. Wait for confirmation window
3. Blow up commander

[Uveso]

Tested;

It will lead to this error:

WARNING: Error running HandleEvent script in CScriptObject at 17507140: ...mdata\faforever\repo\fa\lua\ui\game\construction.lua(2145): attempt to call method `GetEntityId' (a nil value)
         stack traceback:
         	...mdata\faforever\repo\fa\lua\ui\game\construction.lua(2145): in function `FormatData'
         	...mdata\faforever\repo\fa\lua\ui\game\construction.lua(1288): in function `OrderEnhancement'
         	...mdata\faforever\repo\fa\lua\ui\game\construction.lua(1531): in function <...mdata\faforever\repo\fa\lua\ui\game\construction.lua:1530>
         	c:\programdata\faforever\repo\fa\lua\ui\uiutil.lua(873): in function `OnClick'
         	c:\programdata\faforever\repo\fa\lua\ui\uiutil.lua(937): in function <c:\programdata\faforever\repo\fa\lua\ui\uiutil.lua:933>
         	c:\programdata\faforever\repo\fa\lua\ui\uiutil.lua(797): in function <c:\programdata\faforever\repo\fa\lua\ui\uiutil.lua:788>

:GetEntityId() is called on the destroyed commander.