[gnome-contacts] Store: don't calculate Hashmap.get_keys() twice.

[Niels De Graef <nielsdg src gnome org>]

commit 1a41ed2010b05305d8e25a1cbd68504cb83d0ecc
Author: Niels De Graef <nielsdegraef gmail com>
Date:   Sat Apr 7 13:58:36 2018 +0200

    Store: don't calculate Hashmap.get_keys() twice.

 src/contacts-store.vala | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/src/contacts-store.vala b/src/contacts-store.vala
index b4836b8..1638031 100644
--- a/src/contacts-store.vala
+++ b/src/contacts-store.vala
@@ -175,11 +175,11 @@ public class Contacts.Store : GLib.Object {
   private void on_individuals_changed_detailed (MultiMap<Individual?,Individual?> changes) {
     // Note: Apparently the current implementation doesn't necessarily pick
     // up unlinked individual as replacements.
-
     var replaced_individuals = new HashMap<Individual?, Individual?> ();
+    var old_individuals = changes.get_keys();
 
     // Pick best replacements at joins
-    foreach (var old_individual in changes.get_keys ()) {
+    foreach (var old_individual in old_individuals) {
       if (old_individual == null)
         continue;
       foreach (var new_individual in changes[old_individual]) {
@@ -192,7 +192,7 @@ public class Contacts.Store : GLib.Object {
       }
     }
 
-    foreach (var old_individual in changes.get_keys ()) {
+    foreach (var old_individual in old_individuals) {
       HashSet<Individual>? replacements = null;
       foreach (var new_individual in changes[old_individual]) {
         if (old_individual != null && new_individual != null &&