#3 Worship button looks active before Piety is high enough

[David Bolton]

Steps to reproduce:
1. Start a game where you have less than 1000 piety
2. Click on the "Diety" tab

Expected behavior:
The "Worship" button should appear with grey text to indicate that the button is not yet active

Actual behavior:
The "Worship" button appears with black text suggesting that the button is active (even though clicking it does nothing).