Protecting a non-existent page goes through but displays an error
```
[96760c558831f732dbed3730] /Test_Page TypeError from line 114 of /home/hydra/public_html/extensions/CategorySkins/CategorySkins.hooks.php: Argument 3 passed to CategorySkinsHooks::onSkinTemplateBuildNavUrlsNav_urlsAfterPermalink() must be of the type int, null given, called in /home/hydra/public_html/includes/Hooks.php on line 174
Backtrace:
#0 /home/hydra/public_html/includes/Hooks.php(174): CategorySkinsHooks::onSkinTemplateBuildNavUrlsNav_urlsAfterPermalink(SkinHydraDark, array, NULL, NULL)
#1 /home/hydra/public_html/includes/Hooks.php(202): Hooks::callHook(string, array, array, NULL)
#2 /home/hydra/public_html/includes/skins/SkinTemplate.php(1322): Hooks::run(string, array)
#3 /home/hydra/public_html/includes/skins/SkinTemplate.php(470): SkinTemplate->buildNavUrls()
#4 /home/hydra/public_html/includes/skins/SkinTemplate.php(228): SkinTemplate->prepareQuickTemplate()
#5 /home/hydra/public_html/includes/OutputPage.php(2723): SkinTemplate->outputPage()
#6 /home/hydra/public_html/includes/MediaWiki.php(872): OutputPage->output(boolean)
#7 /home/hydra/public_html/includes/MediaWiki.php(884): MediaWiki->{closure}()
#8 /home/hydra/public_html/includes/MediaWiki.php(515): MediaWiki->main()
#9 /home/hydra/public_html/index.php(42): MediaWiki->run()
#10 {main}
```
Steps to recreate:
* Go to a page that doesn't exist
* Protect it
The protection action will go through as seen in logs, but you get an error like this.
issue