added fix for blocks undefined when inserting new design library entry

Author: [email protected]

src/block/design-library/edit.js

@@ -111,7 +111,7 @@ const createBlockWithAttributes = ( blockName, attributes, innerBlocks, design )
 
 	// Recursively update the attributes of all inner blocks for the new Color Picker
 	const migrateToNewColorPicker = blocks => {
-		blocks.forEach( block => {
+		blocks?.forEach( block => {
 			let newAttributes = block[ 1 ]
 			newAttributes = deprecateContainerBackgroundColorOpacity.migrate( newAttributes )
 			newAttributes = deprecateBlockBackgroundColorOpacity.migrate( newAttributes )