Fixed StackOverflow in OpenAPI generator on 1-1 relations

Plugins/OpenApi/src/main/java/de/fraunhofer/iosb/ilt/frostserver/plugin/openapi/spec/OpenApiGenerator.java

@@ -441,7 +441,7 @@ private static void addPathsForEntity(OADoc document, int level, Map<String, OAP
                 String baseName = base + "/" + type.entityName;
                 OAPath paPath = createPathForEntity(options, baseName, type);
                 paths.put(baseName, paPath);
-                addPathsForEntity(document, level, paths, baseName, type, options);
+                addPathsForEntity(document, level + 1, paths, baseName, type, options);
             }
         }
     }