Fix TextBox template binding.
Fix TextBox template binding.

jkoritzinsky/Avalonia,jkoritzinsky/Avalonia,AvaloniaUI/Avalonia,MrDaedra/Avalonia,punker76/Perspex,MrDaedra/Avalonia,akrisiun/Perspex,grokys/Perspex,jkoritzinsky/Avalonia,susloparovdenis/Avalonia,wieslawsoltes/Perspex,jkoritzinsky/Avalonia,SuperJMN/Avalonia,AvaloniaUI/Avalonia,wieslawsoltes/Perspex,Perspex/Perspex,jkoritzinsky/Perspex,AvaloniaUI/Avalonia,AvaloniaUI/Avalonia,OronDF343/Avalonia,jazzay/Perspex,SuperJMN/Avalonia,AvaloniaUI/Avalonia,AvaloniaUI/Avalonia,wieslawsoltes/Perspex,jkoritzinsky/Avalonia,OronDF343/Avalonia,wieslawsoltes/Perspex,wieslawsoltes/Perspex,Perspex/Perspex,grokys/Perspex,susloparovdenis/Avalonia,SuperJMN/Avalonia,wieslawsoltes/Perspex,SuperJMN/Avalonia,susloparovdenis/Perspex,jkoritzinsky/Avalonia,jkoritzinsky/Avalonia,wieslawsoltes/Perspex,AvaloniaUI/Avalonia,susloparovdenis/Perspex,SuperJMN/Avalonia,SuperJMN/Avalonia,SuperJMN/Avalonia