bump the default battery poll time to 1 minute

It turns out this polling has a non-trivial impact on battery life, and
probably nobody cares about up to the second battery life updates. So,
let's not poll so often.

libqtile/widget/battery.py

@@ -85,7 +85,7 @@ class _Battery(base._TextBox):
             'Name of file with the current'
             ' power draw in /sys/class/power_supply/battery_name'
         ),
-        ('update_delay', 1, 'The delay in seconds between updates'),
+        ('update_delay', 60, 'The delay in seconds between updates'),
     ]
 
     def __init__(self, **config):