tweaks: Update setting defaults.

`video_grace_period` now 90 seconds.
`task_limit` now 99.
`rent_member_limit` now 24.

Also updated `Integer` default `_min` and `_max` to match DB values.

bot/settings/setting_types.py

@@ -130,8 +130,8 @@ class Integer(SettingType):
     accepts = "An integer."
 
     # Set limits on the possible integers
-    _min = -4096
-    _max = 4096
+    _min = -2147483647
+    _max = 2147483647
 
     @classmethod
     def _data_from_value(cls, id: int, value: Optional[bool], **kwargs):