[polari] entryArea: Use is_focus() method instead of property

[Florian Müllner <fmuellner src gnome org>]

commit 5faeb3973a68b42de5ef5472167d680a9ea98bf3
Author: Florian Müllner <fmuellner gnome org>
Date:   Thu Jul 20 20:35:11 2017 +0200

    entryArea: Use is_focus() method instead of property
    
    Just like GtkWidget:has-focus in the previous commit, :is-focus is
    shadowed by the method of the same name ...

 src/entryArea.js |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/entryArea.js b/src/entryArea.js
index 33b692c..485af8e 100644
--- a/src/entryArea.js
+++ b/src/entryArea.js
@@ -422,7 +422,7 @@ var EntryArea = new Lang.Class({
         this._nickLabel.width_chars = Math.max(nick.length, this._maxNickChars);
         this._nickLabel.label = nick;
 
-        if (!this._nickEntry.is_focus)
+        if (!this._nickEntry.is_focus())
             this._nickEntry.text = nick;
     },