Revert "Fixed width table layout so that it doesn't shift while loading"

That change made it unreadable on small screens and apparently
people were using it like that.

This reverts commit 4aa0cf8.

render_stats.rb

@@ -77,12 +77,7 @@ def percent a, b
 	}
 end
 
-puts '<table class="wikitable statistics" style="table-layout: fixed">'
-puts '<colgroup>'
-puts '<col style="width: 12em">'
-puts '<col style="width: 5em">'
-puts '<col style="width: 5em">'
-puts '</colgroup>'
+puts '<table class="wikitable statistics">'
 puts '<tr>'
 puts html('th', "Site", colspan: 2)
 puts html('th', month || "Last 30 days", class: 'summary')