fix: make invalid url actually invalid

I'm using one of those ISPs that 'helpfully' directs you to a search
page if the URL you are accessing does not have a DNS match.

The URL used in the test was well formed but not a real domain though
can be resolved, so this PR changes it to be something even a
web-breaking DNS server would refuse to resolve.

src/files-regular/add-from-url.js

@@ -120,7 +120,7 @@ module.exports = (createCommon, options) => {
     })
 
     it('should not add from an invalid url', (done) => {
-      ipfs.addFromURL('http://invalid', (err, result) => {
+      ipfs.addFromURL('123http://invalid', (err, result) => {
         expect(err).to.exist()
         expect(result).to.not.exist()
         done()