Add null guard to tag parsing function to prevent parsing values that don't match tag RegEx.

ui/src/hosts/apis/index.js

@@ -196,6 +196,7 @@ function parseSeries(series) {
   function parseTag(s, obj) {
     const match = tag.exec(s)
 
+    if (match) {
       const kv = match[0]
       const key = match[1]
       const value = match[2]
@@ -209,6 +210,9 @@ function parseSeries(series) {
       return s.slice(match.index + kv.length)
     }
 
+    return ''
+  }
+
   let workStr = series.slice()
   const out = {}