fix(npm-scripts): don't fail for default exports

When an `export default ...` is placed in a file the build failed unless it was an
`export default ... from ...`.

Author: izaera

projects/npm-tools/packages/npm-scripts/src/transform/js/relocateImports.js

@@ -50,6 +50,7 @@ module.exports = function (previousDirRelPath) {
 
 				if (
 					NODE_TYPES.has(node.type) &&
+					source &&
 					source.value.startsWith('./')
 				) {
 					source.value = source.value.replace(/^\./, dotReplacement);