Fix display of tabs label #520

Author: taniki

src/Tabset.vue

@@ -4,7 +4,7 @@
     <ul class="nav nav-{{navStyle}}" role="tablist">
       <template v-for="t in headers">
         <li v-if="!t._tabgroup" :class="{active:t.active, disabled:t.disabled}" @click.prevent="select(t)">
-          <a href="#"><slot name="header" v-html="t.header"></slot></a>
+          <a href="#"><slot name="header">{{{ t.header }}}</slot></a>
         </li>
         <dropdown v-else :text="t.header" :class="{active:t.active}" :disabled="t.disabled">
           <li v-for="tab in t.tabs" :class="{disabled:tab.disabled}"><a href="#" @click.prevent="select(tab)">{{tab.header}}</a></li>