Fix current user owner check

apps/project/mutation.py

@@ -359,10 +359,10 @@ class LeaveProject(ProjectScopeMixin, graphene.Mutation):
     def mutate(cls, root, info, **kwargs):
         project = info.context.active_project
         serializer = UserProjectLeaveSerializer(data={}, context={'request': info.context.request})
-        if serializer.is_valid():
-            serializer.save()
-            return LeaveProject(ok=True, result=project)
-        return LeaveProject(ok=False, errors=serializer.errors)
+        if errors := mutation_is_not_valid(serializer):
+            return LeaveProject(errors=errors, ok=False)
+        serializer.save()
+        return LeaveProject(result=project, errors=None, ok=True)
 
 
 class ProjectMutationType(

apps/project/serializers.py

@@ -972,7 +972,7 @@ def validate(self, data):
 
         if (
             membership.filter(role=ProjectRole.get_owner_role()).count() == 1 and
-            membership.member == self.current_user
+            membership.filter(member=self.current_user)
         ):
             raise serializers.ValidationError('Last owner of project can\'t leave')
         return data