Map http://d-nb.info/ to the GND

src/enums/MDNodaRepository.php

@@ -64,6 +64,7 @@ public static function fromString(string $input):MDNodaRepository {
             'o-gnd'     => self::gnd,
             'O-GND'     => self::gnd,
             'pnd'       => self::gnd,
+            'http://d-nb.info/' => self::gnd, // This is technically wrong, but used in practice...
             'http://d-nb.info/gnd'  => self::gnd,
             'http://d-nb.info/gnd/' => self::gnd,
             'd-nb.info'             => self::gnd,