[gnome-build-meta] core-deps/libgit2: fix the name of cmake feature

[Jordan Petridis <jpetridis src gnome org>]

commit 536946cce801228e4d6c4e8333cb0aa202c6e258
Author: Jordan Petridis <jordan centricular com>
Date:   Fri Jul 15 01:55:01 2022 +0300

    core-deps/libgit2: fix the name of cmake feature
    
    It was renamed

 elements/core-deps/libgit2.bst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/elements/core-deps/libgit2.bst b/elements/core-deps/libgit2.bst
index 339f5aed1..96cab0e5c 100644
--- a/elements/core-deps/libgit2.bst
+++ b/elements/core-deps/libgit2.bst
@@ -10,4 +10,4 @@ depends:
 variables:
   cmake-local: >-
     -DLIB_INSTALL_DIR:PATH=%{libdir}
-    -DTHREADSAFE:BOOL=1
+    -DUSE_THREADS:BOOL=ON