Changed the check on TextContainer default values to allow False-evaluated defaults.

gooey/gui/components/widgets/bases.py

@@ -56,7 +56,8 @@ class TextContainer(BaseWidget):
         self.setColors()
         self.SetSizer(self.layout)
         self.Bind(wx.EVT_SIZE, self.onSize)
-        if self._meta['default']:
+        # Checking for None instead of truthiness means False-evaluaded defaults can be used.
+        if self._meta['default'] is not None:
             self.setValue(self._meta['default'])