fix: Use default_avatar where needed.

src/modules/pomodoro/graphics.py

@@ -36,7 +36,7 @@ async def get_timer_card(bot: LionBot, timer: 'Timer', stage: 'Stage'):
             tag = None
 
         card_user = (
-            (member.id, member.avatar.key),
+            (member.id, (member.avatar or member.default_avatar).key),
             session_duration,
             tag,
         )

src/modules/schedule/ui/scheduleui.py

@@ -437,7 +437,7 @@ class ScheduleUI(MessageUI):
                 'ui:schedule|embed|author',
                 "Your Scheduled Sessions and Past Statistics"
             )).format(name=member.display_name if member else self.lion.luser.data.name),
-            icon_url=self.lion.member.avatar
+            icon_url=(self.lion.member.avatar or self.lion.member.default_avatar)
         )
         if self.show_info:
             # Info message

src/modules/statistics/graphics/profile.py

@@ -29,7 +29,7 @@ async def get_profile_card(bot: LionBot, userid: int, guildid: int):
 
     if member:
         username = (member.display_name, '#' + str(member.discriminator))
-        avatar = member.avatar.key
+        avatar = member.avatar.key if member.avatar else member.default_avatar.key
     else:
         username = (lion.data.display_name, "#????")
         avatar = luser.data.avatar_hash