Fix more spacing and layout issues

dashboard/src/components/app/Security.vue

@@ -61,9 +61,9 @@ onMounted(() => {
           <textarea id="cspInput" style="white-space: pre-wrap; font-family: monospace;" v-model="csp" placeholder="default-src 'self'; frame-ancestors 'none';" rows="2"></textarea>
         </FormGroup>
 
-        <Checkbox v-model="hstsPreload" style="display: inline-flex;" :label="$t('app.security.hstsPreload')" help-url="https://docs.cloudron.io/apps/#hsts-preload"/>
-
-        <br/>
+        <div>
+          <Checkbox v-model="hstsPreload" style="display: inline-flex;" :label="$t('app.security.hstsPreload')" help-url="https://docs.cloudron.io/apps/#hsts-preload"/>
+        </div>
 
         <Button @click="onSubmit()" :loading="busy" :disabled="busy">{{ $t('app.security.csp.saveAction') }}</Button>
       </fieldset>