vue/promql-query: Use same delimiters as the Vue app

Using different delimiters in different components can be error prone and
confusing. Is better to stick to one kind of delimiters and use it always, for
the previous reasons and also for consistency.

promgen/static/js/promgen.vue.js

@@ -188,6 +188,7 @@ Vue.filter("time", function (value, fmtstr = "yyyy-MM-dd HH:mm:ss") {
 });
 
 Vue.component("promql-query", {
+    delimiters: ['[[', ']]'],
     props: ["href", "query", "max"],
     data: function () {
         return {

promgen/templates/promgen/vue/promql_query.html

@@ -1,3 +1,3 @@
 <span style="display: none" :title="load | percent" :class="classes">
-  {{ count | localize }} <slot></slot>
+  [[ count | localize ]] <slot></slot>
 </span>