Fixing getArticleRoute() calls

There is no need to use catslug in Joomla 3.x because:
1. Core content component doesn't use catslug in article URLs;
2. Process link function - **ContentHelperRoute::getArticleRoute** - requires only catid.
`/components/com_content/helpers/route.php`
`public static function getArticleRoute($id, $catid = 0, $language = 0)`

See more #4371 and #5276

After this PR all URLs to the articles must be identical as in content component.
Fixing getArticleRoute() calls

There is no need to use catslug in Joomla 3.x because:
1. Core content component doesn't use catslug in article URLs;
2. Process link function - **ContentHelperRoute::getArticleRoute** - requires only catid.
`/components/com_content/helpers/route.php`
`public static function getArticleRoute($id, $catid = 0, $language = 0)`

See more #4371 and #5276

After this PR all URLs to the articles must be identical as in content component.
Two more index.html found

Should we expel those two rascals?
Merge pull request #5467 from smz/TwoMoreIndexHTML

Two more index.html found
Changed Allow User Registration setting to OFF for new Joomla installations
Merge pull request #5468 from pe7er/AllowUserRegistrationOFF

Changed Allow User Registration setting to OFF for new Joomla installati...
The neverending story of index.html

Two more...
Updated script.php
Fix clear button
updatesites
Merge pull request #5473 from losedk/clear

Fix clear button in discover view
Merge pull request #5471 from smz/MoreIndexHTML

The neverending story of index.html
Update README.md

updated few Migration links to the JDocs
Update README.txt

Few migration links updated
Update README.txt

docs links -> https
Merge pull request #5480 from MAT978/patch-11

Update README.txt
Update README.md

docs links -> https
API site serves all traffic via HTTPS
Merge pull request #5479 from MAT978/patch-10

Update README.md
Merge pull request #5481 from mbabker/APIlinks

API site serves all traffic via HTTPS