patch 9.1.0682: Vim9: Segfault with uninitialized funcref

Problem:  Vim9: Segfault with uninitialized funcref
          (Daniel Viberg)
Solution: Check the Funcref for being Null before trying to access it
          (Ernie Rael)

fixes: #15523

Signed-off-by: Ernie Rael <errael@raelity.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index d07bbfb..030ff83 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
Binary files differ