Configuration: Allow unquoted special characters in config.ini

Quoted strings will still work but not escaping within them with a backslash.
Also disables some other stuff like using `off`/`none`/`no`/`false` literals for booleans (`0` still works) or variable interpolation.

https://www.php.net/manual/en/function.parse-ini-file.php

Fixes: #1371

NEWS.md

@@ -1,4 +1,10 @@
 # selfoss news
+## 2.20 – unreleased
+
+### Bug fixes
+- Configuration parser was changed to *raw* method, which relaxes the requirement to quote option values containing special characters in `config.ini`. ([#1371](https://github.com/fossar/selfoss/issues/1371))
+
+
 ## 2.19 – 2022-10-12
 **This version requires PHP 5.6 or newer. It is also the last version to support PHP 7.**
 

src/helpers/Configuration.php

@@ -171,7 +171,7 @@ class Configuration {
     public function __construct($configPath = null, $environment = []) {
         // read config.ini, if it exists
         if ($configPath !== null && file_exists($configPath)) {
-            $config = parse_ini_file($configPath);
+            $config = parse_ini_file($configPath, false, INI_SCANNER_RAW);
             if ($config === false) {
                 throw new Exception('Error loading config.ini');
             }