[gimp] tools: fix perl warning about unescaped left brace in gimp-mkenums

[Michael Natterer <mitch src gnome org>]

commit 24233bc4ec81a8012c61d7da5ef94d2b85236c25
Author: Michael Natterer <mitch gimp org>
Date:   Thu Jan 3 15:20:33 2019 +0100

    tools: fix perl warning about unescaped left brace in gimp-mkenums
    
    Simply use "\{" instead of "{" for matching a literal "{".
    
    (cherry picked from commit 4a294f6d6a22ce840388f5dc3ba8429191539b2d)

 tools/gimp-mkenums | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/tools/gimp-mkenums b/tools/gimp-mkenums
index 5838fae521..f39103f567 100755
--- a/tools/gimp-mkenums
+++ b/tools/gimp-mkenums
@@ -263,7 +263,7 @@ while (<>) {
     next if /^\s*typedef\s+enum.*;/;
 
     if (m@^\s*typedef\s+enum\s*
-           ({)?\s*
+           (\{)?\s*
            (?:/\*<
              (([^*]|\*(?!/))*)
             >\s*\*/)?