[Misc] fix ring att log (#610)

Signed-off-by: David Chen <530634352@qq.com>

vllm_omni/diffusion/data.py

@@ -500,7 +500,7 @@ def get_cached_compilation_config():
 
 def get_current_omni_diffusion_config() -> OmniDiffusionConfig:
     if _current_omni_diffusion_config is None:
-        logger.warning("Current OmniDiffusionConfig is not set.")
+        logger.warning_once("Current OmniDiffusionConfig is not set.")
         return OmniDiffusionConfig()
     return _current_omni_diffusion_config