leak: manually delete c++ pointers

ARC does not take in charge C++ pointers

Issue: #78372
Change-Id: Ia62d70073e541c0979ef556d8adb3686cfec799e
diff --git a/src/PersonsVC.mm b/src/PersonsVC.mm
index 68687a2..d77471c 100644
--- a/src/PersonsVC.mm
+++ b/src/PersonsVC.mm
@@ -98,6 +98,11 @@
     CategorizedContactModel::instance()->setUnreachableHidden(YES);
 }
 
+- (void) dealloc
+{
+    delete contactProxyModel;
+}
+
 - (IBAction)callContact:(id)sender
 {
     if([[treeController selectedNodes] count] > 0) {