Nasty edge case page_hash bug in sitemap creation

[Xippo]

MetaSEO version: 3.0.0
TYPO3 version: 8.7.18
PHP version: 7.1.16

here the setup:
I have two page trees working as to sparate sites. A and B.
I index pages and typolinks.

I render on both sites something like a site selector. So if we call site B we have two page urls like this '/' to be inserted in the sitemap, but one has the page root uid from site A and the page link from B itself has also the url '/' but a different page uid. So one of this two will not be inserted inside the sitemap because the generation of the page hash is based only on the url and so one will be excluded because the hash is still inside the cache.

i will add the fix.