Merge commit from fork

* Make sheet label plugin not mandatory

* Add max limit for 'skip' parameter

src/backend/InvenTree/plugin/builtin/labels/label_sheet.py

@@ -35,6 +35,7 @@ class LabelPrintingOptionsSerializer(serializers.Serializer):
         label=_('Skip Labels'),
         help_text=_('Skip this number of labels when printing label sheets'),
         min_value=0,
+        max_value=500
     )
 
     border = serializers.BooleanField(

src/backend/InvenTree/plugin/registry.py

@@ -65,7 +65,6 @@ class PluginsRegistry:
         'inventreecorenotificationsplugin',
         'inventreelabel',
         'inventreelabelmachine',
-        'inventreelabelsheet',
         'parameter-exporter',
     ]