autoconf: autoscan: port to perl 5.17

SDL Commits
1

https://github.com/libsdl-org/autoconf/commit/bd723024a95c7a878299948db82194ee6a3cd26f

From bd723024a95c7a878299948db82194ee6a3cd26f Mon Sep 17 00:00:00 2001
From: Paul Eggert <[EMAIL REDACTED]>
Date: Tue, 29 Jan 2013 13:46:48 -0800
Subject: [PATCH] autoscan: port to perl 5.17

* bin/autoscan.in (scan_sh_file): Escape '{'.  This avoids a
feature that is deprecated in Perl 5.17.  Reported by Ray Lauff in
<http://lists.gnu.org/archive/html/bug-autoconf/2013-01/msg00059.html>.
(cherry picked from commit e5654a5591884b92633c7785f325626711e7f7aa)
---
 bin/autoscan.in | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/bin/autoscan.in b/bin/autoscan.in
index a67c48d0..1f9809cc 100644
--- a/bin/autoscan.in
+++ b/bin/autoscan.in
@@ -358,7 +358,7 @@ sub scan_sh_file ($)
     {
       # Strip out comments and variable references.
       s/#.*//;
-      s/\${[^\}]*}//g;
+      s/\$\{[^\}]*}//g;
       s/@[^@]*@//g;
 
       # Tokens in the code.