Fix deleting config keys properly

Author: kyb3r

cogs/modmail.py

@@ -87,9 +87,6 @@ async def _add(self, ctx, name: str.lower, *, value):
     async def __del(self, ctx, *, name: str.lower):
         """Removes a snippet from bot config."""
 
-        if 'snippets' not in self.bot.config.cache:
-            self.bot.config['snippets'] = {}
-
         em = discord.Embed(
             title='Removed snippet',
             color=discord.Color.green(),
@@ -101,7 +98,7 @@ async def __del(self, ctx, *, name: str.lower):
             em.color = discord.Color.red()
             em.description = f'Snippet `{name}` does not exist.'
         else:
-            self.bot.config['snippets'][name] = None
+            del self.bot.config['snippets'][name]
             await self.bot.config.update()
 
         await ctx.send(embed=em)

cogs/utility.py

@@ -392,7 +392,7 @@ async def _del(self, ctx, key: str.lower):
             valid_keys = [f'`{k}`' for k in self.bot.config.allowed_to_change_in_command]
             em.add_field(name='Valid keys', value=', '.join(valid_keys))
         else:
-            self.bot.config.cache[key] = None
+            del self.bot.config.cache[key]
             await self.bot.config.update()
 
         await ctx.send(embed=em)
@@ -498,7 +498,7 @@ async def __del(self, ctx, *, name: str.lower):
             em.color = discord.Color.red()
             em.description = f'Alias `{name}` does not exist.'
         else:
-            self.bot.config['aliases'][name] = None
+            del self.bot.config['aliases'][name]
             await self.bot.config.update()
 
         await ctx.send(embed=em)