Fix a minor PHP CS Fixer warning in SendSEPADirectDebit.php

It's the last remaining warning across the code base.

Author: Philipp91

lib/Fhp/Action/SendSEPADirectDebit.php

@@ -159,7 +159,8 @@ protected function createRequest(BPD $bpd, ?UPD $upd)
                 . implode(', ', $supportedPainNamespaces));
         }
 
-        /** @var mixed $hkdxe */ // TODO Put a new interface type here.
+        // TODO Put a new interface type here.
+        /** @var mixed $hkdxe */
         $hkdxe = $hidxes->createRequestSegment();
         $hkdxe->kontoverbindungInternational = Kti::fromAccount($this->account);
         $hkdxe->sepaDescriptor = $this->painNamespace;