[polari] cleanup: Use some more array destructuring

[Florian Müllner <fmuellner src gnome org>]

commit 571f31710e83f12ca7ec7b7c8d842c9881d32d84
Author: Florian Müllner <fmuellner gnome org>
Date:   Sun Aug 11 15:01:14 2019 +0200

    cleanup: Use some more array destructuring
    
    Array destructuring has been supported by gjs/mozjs for quite some time,
    so we are already using it heavily.
    
    Some places sneaked through however where using destructuring makes sense,
    as an element's position has semantic meaning (instead of just making it
    the first, second, ... element).
    
    https://gitlab.gnome.org/GNOME/polari/merge_requests/133

 src/main.js     | 2 +-
 src/userList.js | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/src/main.js b/src/main.js
index 2d2e9c1..8f0e032 100755
--- a/src/main.js
+++ b/src/main.js
@@ -28,7 +28,7 @@ var LOG_DOMAIN = 'Polari';
 function _makeLogFunction(level) {
     return message => {
         let stack = (new Error()).stack;
-        let caller = stack.split('\n')[1];
+        let [, caller] = stack.split('\n');
 
         // Map from resource- to source location
         caller = caller.replace('resource:///org/gnome/Polari/js', 'src');
diff --git a/src/userList.js b/src/userList.js
index 9384728..07f1846 100644
--- a/src/userList.js
+++ b/src/userList.js
@@ -298,9 +298,9 @@ var UserDetails = GObject.registerClass({
         let info = this._user.get_contact_info();
         for (let i = 0; i < info.length; i++) {
             if (info[i].field_name == 'fn')
-                fn = info[i].field_value[0];
+                [fn] = info[i].field_value;
             else if (info[i].field_name == 'x-idle-time')
-                last = info[i].field_value[0];
+                [last] = info[i].field_value;
         }
 
         if (!fn)