🩹(backend) fix wrong environment variable

Oopsie, wrongly copy-pasted a Django settings leading in
using the wrong environment variable for a new setting.
I should have read my code;

src/backend/meet/settings.py

@@ -489,7 +489,7 @@ class Base(Configuration):
         None, environ_name="SUMMARY_SERVICE_API_TOKEN", environ_prefix=None
     )
     SCREEN_RECORDING_BASE_URL = values.Value(
-        None, environ_name="SUMMARY_SERVICE_API_TOKEN", environ_prefix=None
+        None, environ_name="SCREEN_RECORDING_BASE_URL", environ_prefix=None
     )
 
     # Marketing and communication settings