Replace log error with warning in reflection with type not found

Author: frantuma

modules/swagger-core/src/main/java/io/swagger/v3/core/util/ReflectionUtils.java

@@ -34,7 +34,7 @@ public static Type typeFromString(String type) {
         try {
             return loadClassByName(type);
         } catch (Exception e) {
-            LOGGER.error(String.format("Failed to resolve '%s' into class", type), e);
+            LOGGER.warn(String.format("Failed to resolve '%s' into class", type), e);
         }
         return null;
     }