change http status code

Signed-off-by: Justin Dex <justin.dex@msg-david.de>

src/main/java/eu/gaiax/sdcreationwizard/api/ConversionController.java

@@ -202,7 +202,7 @@ public class ConversionController {
         } catch (IOException e) {
             return new ResponseEntity<>("Shacl conversion failed <-> Bad Input", HttpStatus.BAD_REQUEST);
         } catch (Exception e) {
-            return new ResponseEntity<>("Error: " + e.getMessage(), HttpStatus.BAD_REQUEST);
+            return new ResponseEntity<>("Error: " + e.getMessage(), HttpStatus.INTERNAL_SERVER_ERROR);
         }
         return new ResponseEntity<>(response, HttpStatus.OK);
     }