revised language and approach to import the system check

Adds a rest framework app config.

rest_framework/__init__.py

@@ -6,7 +6,6 @@
 | |\ \| |___/\__/ / | |   | | | | | (_| | | | | | |  __/\ V  V / (_) | |  |   <
 \_| \_\____/\____/  \_/   |_| |_|  \__,_|_| |_| |_|\___| \_/\_/ \___/|_|  |_|\_|
 """
-from .checks import *  # NOQA
 
 __title__ = 'Django REST framework'
 __version__ = '3.6.3'
@@ -22,3 +21,5 @@
 
 # Default datetime input and output formats
 ISO_8601 = 'iso-8601'
+
+default_app_config = 'rest_framework.apps.RestFrameworkConfig'

rest_framework/apps.py

@@ -0,0 +1,10 @@
+from django.apps import AppConfig
+
+
+class RestFrameworkConfig(AppConfig):
+    name = 'rest_framework'
+    verbose_name = "Django REST framework"
+
+    def ready(self):
+        # Add System checks
+        from .checks import pagination_system_check  # NOQA

rest_framework/checks.py

@@ -9,12 +9,10 @@ def pagination_system_check(app_configs, **kwargs):
     if api_settings.PAGE_SIZE and not api_settings.DEFAULT_PAGINATION_CLASS:
         errors.append(
             Warning(
-                "You have specified a default `PAGE_SIZE` pagination rest_framework setting,"
-                "without specifying also a `DEFAULT_PAGINATION_CLASS`.",
-                hint="The prior version of rest_framework defaulted this setting to "
-                "`PageNumberPagination` however pagination defaults to disabled now.  "
-                "Consider specifying `DEFAULT_PAGINATION_CLASS` explicitly for your project, "
-                "unless you specify individual pagination_class values on specific view classes.",
+                "You have specified a default PAGE_SIZE pagination rest_framework setting,"
+                "without specifying also a DEFAULT_PAGINATION_CLASS.",
+                hint="The default for DEFAULT_PAGINATION_CLASS is None. "
+                     "In previous versions this was PageNumberPagination",
             )
         )
     return errors