MDL-22812 Do not change dataroot path passed as argument

Because PARAM_SAFEPATH was applied on dataroot argument, directories
containing dots (eg. /var/www/data/moodle.tld.com) were silently
renamed. The patch removes the input validation on the argument. If the
enemy is executing scripts at the server, you are doomed anyway.

admin/cli/install.php

@@ -311,7 +311,7 @@ $CFG->httpswwwroot  = $CFG->wwwroot;
 
 //We need dataroot before lang download
 if (!empty($options['dataroot'])) {
-    $CFG->dataroot = clean_param($options['dataroot'], PARAM_SAFEPATH);
+    $CFG->dataroot = $options['dataroot'];
 }
 if ($interactive) {
     cli_separator();