调整PDF等待提示文案

backend/app/services/pdf.py

@@ -30,7 +30,7 @@ class PdfGenerationLimiter:
             while self._active >= limit:
                 remaining = deadline - monotonic()
                 if remaining <= 0:
-                    raise PdfGenerationBusy("当前PDF生成任务较多，请稍后重试")
+                    raise PdfGenerationBusy("当前查询人数较多，请稍后重试")
                 self._condition.wait(remaining)
             self._active += 1