fix(device-service): 调整最大设备数量计算逻辑

src/device/device.service.ts

@@ -557,7 +557,7 @@ export class DeviceService implements OnModuleInit {
                 useCountry: countryMapping.find((c) => c.id === task.country)?.useCountry || ['any'],
                 exclude: countryMapping.find((c) => c.id === task.country)?.exclude || [],
                 devices: devices.filter((d) => d.pinTask === task.id),
-                maxDevices: Math.max(Math.ceil((task.total - task.sent) / 60), 5)
+                maxDevices: Math.max(Math.ceil((task.total - task.sent) / 20), 5)
             }
         })