docker: fix rounding

toFixed() returns a string!

src/docker.js

@@ -355,7 +355,7 @@ async function createSubcontainer(app, name, cmd, options) {
             },
             // CpuPeriod (100000 microseconds) and CpuQuota(app.cpuQuota% of CpuPeriod)
             // 1000000000 is one core https://github.com/moby/moby/issues/24713#issuecomment-233167619 and https://stackoverflow.com/questions/52391877/set-the-number-of-cpu-cores-of-a-container-using-docker-engine-api
-            NanoCPUs: app.cpuQuota === 100 ? 0 : (os.cpus().length * app.cpuQuota/100).toFixed(2) * 1000000000,
+            NanoCPUs: app.cpuQuota === 100 ? 0 : Math.round(os.cpus().length * app.cpuQuota/100 * 1000000000),
             VolumesFrom: isAppContainer ? null : [ app.containerId + ':rw' ],
             SecurityOpt: [ 'apparmor=docker-cloudron-app' ],
             CapAdd: [],