[Bugfix] Fix MultiprocessingGPUExecutor.check_health when world_size == 1#5254

simon-mo merged 2 commits intovllm-project:mainvllm-project/vllm:mainfrom

jsato8094:fix/multiproc-gpu-executor-health-checkjsato8094/vllm:fix/multiproc-gpu-executor-health-checkCopy head branch name to clipboard