add ability to purposefully disable voice initialization

there is an issue (not very urgent) where a traceback was shown at any
`manage.py` usage. this was not catched before because of recent
modifications that removed manager startup when calling `migrate`.

litecord/voice/lvsp_manager.py

@@ -56,7 +56,7 @@ class LVSPManager:
         # quick storage for Region dataclass instances.
         self._regions = {}
 
-        self.app.loop.create_task(self._spawn())
+        self.app.sched.spawn(self._spawn())
 
     async def _spawn(self):
         """Spawn LVSPConnection for each region."""

manage/main.py

@@ -40,8 +40,12 @@ class FakeApp:
     ratelimiter = None
     state_manager = None
     storage = None
+    user_storage = None
+    icons = None
     dispatcher = None
     presence = None
+    voice = None
+    guild_store = None
 
 
 def init_parser():
@@ -76,7 +80,7 @@ def main(config):
         # as the managers require it
         # and the migrate command also sets the db up
         if argv[1] != 'migrate':
-            init_app_managers(app)
+            init_app_managers(app, voice=False)
 
         args = parser.parse_args()
         loop.run_until_complete(args.func(app, args))

run.py

@@ -230,7 +230,7 @@ async def init_app_db(app_):
     app_.sched = JobManager()
 
 
-def init_app_managers(app_):
+def init_app_managers(app_, *, voice=True):
     """Initialize singleton classes."""
     app_.loop = asyncio.get_event_loop()
     app_.ratelimiter = RatelimitManager(app_.config.get('_testing'))
@@ -246,7 +246,13 @@ def init_app_managers(app_):
 
     app_.storage.presence = app_.presence
 
+    # only start VoiceManager if needed.
+    # we do this because of a bug on ./manage.py where it
+    # cancels the LVSPManager's spawn regions task. we don't
+    # need to start it on manage time.
+    if voice:
         app_.voice = VoiceManager(app_)
+
     app_.guild_store = GuildMemoryStore()