Compiling Error popover. Vue2

https://github.com/yuche/vue-strap/blob/master/src/Popover.vue line 13 causes error

 [Vue warn]: failed to compile template:

 <span v-el:trigger> <slot></slot> <div v-el:popover v-if=show 
:class="['popover',placement]" :transition=effect> 
<div class=arrow></div> <h3 class=popover-title v-if=title> 
<slot name=title>{{title}}</slot> 
</h3> <div class=popover-content> <slot name=content>{{{content}}}</slot> 
</div> </div> </span>
    - invalid expression: {{{content}}}
    (found in component <popover>)

related to this PR https://github.com/yuche/vue-strap/pull/472