add ditto headers to generic exception too

Signed-off-by: Dominik Guggemos <dominik.guggemos@bosch-si.com>

signals/commands/things/src/main/java/org/eclipse/ditto/signals/commands/things/ThingErrorResponse.java

@@ -185,6 +185,7 @@ public static ThingErrorResponse fromJson(final ThingErrorRegistry thingErrorReg
                             HttpStatusCode.forInt(status).orElse(HttpStatusCode.INTERNAL_SERVER_ERROR))
                             .message(errorMessage)
                             .description(errorDescription)
+                            .dittoHeaders(dittoHeaders)
                             .build();
         }