[gnome-builder] build: update libgit2 builds

[Christian Hergert <chergert src gnome org>]

commit 7a93bd76aa622b2fcf6daa8ea29ba24ff20ed5c8
Author: Christian Hergert <chergert redhat com>
Date:   Fri Feb 11 13:51:19 2022 -0800

    build: update libgit2 builds

 build-aux/flatpak/org.gnome.Builder.json | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/build-aux/flatpak/org.gnome.Builder.json b/build-aux/flatpak/org.gnome.Builder.json
index 2099e1a0e..719c37c2e 100644
--- a/build-aux/flatpak/org.gnome.Builder.json
+++ b/build-aux/flatpak/org.gnome.Builder.json
@@ -247,13 +247,14 @@
             "config-opts" : [
                 "-DCMAKE_BUILD_TYPE=RelWithDebInfo",
                 "-DBUILD_SHARED_LIBS:BOOL=ON",
-                "-DTHREADSAFE=ON"
+                "-DUSE_SSH=ON",
+                "-DUSE_THREADS=ON"
             ],
             "sources" : [
                 {
                     "type" : "git",
                     "url" : "https://github.com/libgit2/libgit2.git";,
-                    "branch" : "maint/v0.28"
+                    "branch" : "main"
                 }
             ]
         },