Fix `Minimum Font Size greater than current font size` warning

ThaiTechEventsCalendar/Views/Cells/EventTableViewCell.xib: Minimum Font Size greater than current font size

<img width="449" alt="screen shot 2018-02-25 at 16 09 33" src="https://user-images.githubusercontent.com/500289/36639037-6cd8e40e-1a46-11e8-8537-f9c699038877.png">
