remove coverage ignore comments since we are not using coverage anyway

Author: yyx990803

src/components/link.js

@@ -84,16 +84,12 @@ export default {
 
 function guardEvent (e) {
   // don't redirect with control keys
-  /* istanbul ignore if */
   if (e.metaKey || e.ctrlKey || e.shiftKey) return
   // don't redirect when preventDefault called
-  /* istanbul ignore if */
   if (e.defaultPrevented) return
   // don't redirect on right click
-  /* istanbul ignore if */
   if (e.button !== undefined && e.button !== 0) return
   // don't redirect if `target="_blank"`
-  /* istanbul ignore if */
   if (e.target && e.target.getAttribute) {
     const target = e.target.getAttribute('target')
     if (/\b_blank\b/i.test(target)) return