fix linter

Author: mkovalua

api/draft_registrations/serializers.py

@@ -98,7 +98,7 @@ class DraftRegistrationSerializer(DraftRegistrationLegacySerializer, Taxonomizab
     )
 
     has_project = ser.SerializerMethodField()
-    default_license_id = ser.CharField(source="provider.default_license._id", read_only=True, default='')
+    default_license_id = ser.CharField(source='provider.default_license._id', read_only=True, default='')
 
     def get_has_project(self, obj):
         return obj.has_project
@@ -165,7 +165,7 @@ class DraftRegistrationDetailSerializer(DraftRegistrationSerializer, DraftRegist
         'self': 'get_self_url',
     })
 
-    default_license_id = ser.CharField(source="provider.default_license._id", read_only=True, default='')
+    default_license_id = ser.CharField(source='provider.default_license._id', read_only=True, default='')
 
     def get_self_url(self, obj):
         return absolute_reverse(

api/preprints/serializers.py

@@ -254,7 +254,7 @@ class PreprintSerializer(TaxonomizableSerializerMixin, MetricsSerializerMixin, J
     why_no_prereg = ser.CharField(required=False, allow_blank=True, allow_null=True)
     prereg_links = ser.ListField(child=ser.URLField(), required=False)
     prereg_link_info = ser.ChoiceField(Preprint.PREREG_LINK_INFO_CHOICES, required=False, allow_blank=True)
-    default_license_id = ser.CharField(source="provider.default_license._id", read_only=True, default='')
+    default_license_id = ser.CharField(source='provider.default_license._id', read_only=True, default='')
 
     class Meta:
         type_ = 'preprints'