Remove duplicate checks

Originally, these checks were the same as the checks in OrderChangeManager, but now that OrderChangeManager respects pre-existing but unavailable addons, they are not accurate any more.

src/pretix/presale/views/order.py

@@ -79,7 +79,7 @@ from pretix.base.services.invoices import (
 )
 from pretix.base.services.orders import (
     OrderChangeManager, OrderError, _try_auto_refund, cancel_order,
-    change_payment_provider, error_messages,
+    change_payment_provider,
 )
 from pretix.base.services.pricing import get_price
 from pretix.base.services.tickets import generate, invalidate_cache
@@ -1592,30 +1592,6 @@ class OrderChangeMixin:
                 if val:
                     selected[i, None] = val, price
 
-        if sum(a[0] for a in selected.values()) > category['max_count']:
-            raise ValidationError(
-                error_messages['addon_max_count'] % {
-                    'base': str(form['pos'].item.name),
-                    'max': category['max_count'],
-                    'cat': str(category['category'].name),
-                }
-            )
-        elif sum(a[0] for a in selected.values()) < category['min_count']:
-            raise ValidationError(
-                error_messages['addon_min_count'] % {
-                    'base': str(form['pos'].item.name),
-                    'min': category['min_count'],
-                    'cat': str(category['category'].name),
-                }
-            )
-        elif any(sum(v[0] for k, v in selected.items() if k[0] == i) > 1 for i in category['items']) and not category['multi_allowed']:
-            raise ValidationError(
-                error_messages['addon_no_multi'] % {
-                    'base': str(form['pos'].item.name),
-                    'cat': str(category['category'].name),
-                }
-            )
-
         return selected
 
     def post(self, request, *args, **kwargs):