Do not raise error when channels is not installed (#3203)

Author: antonpirker

sentry_sdk/integrations/django/__init__.py

@@ -325,14 +325,10 @@ def sentry_patched_drf_initial(self, request, *args, **kwargs):
 def _patch_channels():
     # type: () -> None
     try:
-        # Django < 3.0
         from channels.http import AsgiHandler  # type: ignore
     except ImportError:
-        try:
-            # DJango 3.0+
-            from django.core.handlers.asgi import ASGIHandler as AsgiHandler
-        except ImportError:
-            return
+        return
+
     if not HAS_REAL_CONTEXTVARS:
         # We better have contextvars or we're going to leak state between
         # requests.

sentry_sdk/integrations/django/asgi.py

@@ -134,8 +134,8 @@ async def sentry_patched_get_response_async(self, request):
 
 def patch_channels_asgi_handler_impl(cls):
     # type: (Any) -> None
-
     import channels  # type: ignore
+
     from sentry_sdk.integrations.django import DjangoIntegration
 
     if channels.__version__ < "3.0.0":