configure: fix test -f for rust/vendor, should be -e

Introduced with commit: c08ec8d8b27280e2bcb066c9caa24da97e0419ee

diff --git a/configure.ac b/configure.ac
index 4497c18ac362901e437a93fa7735b703d97b07e4..9791d982f029a7aafebe5845f4fb1fe078a0a72c 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -2439,7 +2439,7 @@ fi
     AC_SUBST([RUSTUP_HOME_PATH], [$rustup_home_path])
     AC_SUBST([rustup_home])
 
-    if test -f "$srcdir/rust/vendor"; then
+    if test -e "$srcdir/rust/vendor"; then
       have_rust_vendor="yes"
     fi