fix: check before lower case

lib/datasource/npm.js

@@ -147,7 +147,7 @@ async function getDependencyInner(name, retries = 5) {
       retries: 5,
       headers,
     })).body;
-    if (res.name.toLowerCase() !== name.toLowerCase()) {
+    if (!(res.name && res.name.toLowerCase() === name.toLowerCase())) {
       logger.warn(
         { lookupName: name, returnedName: res.name, regUrl },
         'Returned name does not match with requested name'