Only showing the tags that size > 0

No meaning to show the tag that has empty List
The tag which is only used in the note(s) in the Trash, tags.size becomes zero. In order to support this case, filtering tagList is needed

browser/main/SideNav/index.js

@@ -148,7 +148,9 @@ class SideNav extends React.Component {
     const relatedTags = this.getRelatedTags(this.getActiveTags(location.pathname), data.noteMap)
     let tagList = _.sortBy(data.tagNoteMap.map(
       (tag, name) => ({ name, size: tag.size, related: relatedTags.has(name) })
-    ), ['name'])
+    ), ['name']).filter(
+      tag => tag.size > 0
+    )
     if (config.sortTagsBy === 'COUNTER') {
       tagList = _.sortBy(tagList, item => (0 - item.size))
     }