fixed value error

client/components/relativetime/index.jsx

@@ -8,11 +8,14 @@ import React from 'react'
 export default class RelativeTime extends React.Component {
 
   render() {
-    let time = moment.utc(this.props.value);
+    if (!this.props.value) {
+      return null;
+    }
 
+    let time = moment.utc(this.props.value);
     return (
       <span>{time.fromNow(this.props.suffix)}</span>
-    )
+    );
   }
 }