Bots break on explosion damage/death

[NightShr00m]

Dying to explosion related stuff like explosive barrels causes the bots break and to stop moving.

After dying or getting hit by an explosion causes this:

[leadbot-master] addons/leadbot-master/lua/entities/leadbot_navigator.lua:87: Tried to use a NULL entity!

1. EyePos - [C]:-1
2. InFOV - addons/leadbot-master/lua/entities/leadbot_navigator.lua:87
   3. CanSee - addons/leadbot-master/lua/entities/leadbot_navigator.lua:108
   4. PlayerMove - addons/leadbot-master/lua/leadbot/base.lua:388
   5. fn - addons/leadbot-master/lua/leadbot/base.lua:535
   6. unknown - lua/ulib/shared/hook.lua:115 (x26151)