[babl] reduce default max babl path to 3

[Øyvind Kolås <ok src gnome org>]

commit 57a08bf9fd24ee18dbb31be794e4387314157ca5
Author: Øyvind Kolås <pippin gimp org>
Date:   Tue Nov 15 15:47:58 2016 +0100

    reduce default max babl path to 3
    
    Big decrease in combinatorial explosion of search - missing out on some big
    fish.

 babl/babl-fish-path.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/babl/babl-fish-path.c b/babl/babl-fish-path.c
index c8ba588..ebbdd9e 100644
--- a/babl/babl-fish-path.c
+++ b/babl/babl-fish-path.c
@@ -126,7 +126,10 @@ static int max_path_length (void)
   if (env)
     max_length = atoi (env);
   else
-    max_length = 4;
+    max_length = 3; /* reducing this number makes finding short fishes much
+                       faster - even if we lose out on some of the fast
+                       bigger fish
+                     */
   if (max_length > BABL_HARD_MAX_PATH_LENGTH)
     max_length = BABL_HARD_MAX_PATH_LENGTH;
   else if (max_length <= 0)