[gitg] Correct behaviour of --standalone option

[Alberto Fanjul <albfan src gnome org>]

commit d67cbfe7f1afcd95c7dad835a3cf24f973f5af62
Author: Alberto Fanjul <albertofanjul gmail com>
Date:   Tue Oct 4 10:14:41 2022 +0200

    Correct behaviour of --standalone option
    
    if not present git should allow to open several instances
    make this default for desktop, allowing use Primary key to open a new instance

 data/org.gnome.gitg.desktop.in.in | 4 ++--
 gitg/gitg-application.vala        | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/data/org.gnome.gitg.desktop.in.in b/data/org.gnome.gitg.desktop.in.in
index 8cb494bb..4a2ece9e 100644
--- a/data/org.gnome.gitg.desktop.in.in
+++ b/data/org.gnome.gitg.desktop.in.in
@@ -1,7 +1,7 @@
 [Desktop Entry]
 Name=@binary@
 Comment=Git repository browser
-Exec=@binary@ --no-wd --standalone %U
+Exec=@binary@ --no-wd %U
 TryExec=@binary@
 Terminal=false
 Type=Application
@@ -14,4 +14,4 @@ Actions=new-window;
 
 [Desktop Action new-window]
 Name=New Window
-Exec=@binary@ --no-wd --standalone %U
+Exec=@binary@ --no-wd %U
diff --git a/gitg/gitg-application.vala b/gitg/gitg-application.vala
index 6294d965..6802dceb 100644
--- a/gitg/gitg-application.vala
+++ b/gitg/gitg-application.vala
@@ -149,7 +149,7 @@ public class Application : Gtk.Application
                        return true;
                }
 
-               if (standalone)
+               if (!standalone)
                {
                        set_flags(get_flags() | ApplicationFlags.NON_UNIQUE);
                }