mutt: Add NONULL to debug statement in fold_one_header().

[Brendan Cully]

changeset: 7185:7b21142450dd
user:      Anton Lindqvist <anton.lindqv...@gmail.com>
date:      Sun Nov 19 15:47:45 2017 -0800
link:      http://dev.mutt.org/hg/mutt/rev/7b21142450dd

Add NONULL to debug statement in fold_one_header().

diffs (12 lines):

diff -r 6e8050965f1a -r 7b21142450dd sendlib.c
--- a/sendlib.c Sat Nov 18 19:13:08 2017 -0800
+++ b/sendlib.c Sun Nov 19 15:47:45 2017 -0800
@@ -1684,7 +1684,7 @@
   int first = 1, enc, col = 0, w, l = 0, fold;
 
   dprint(4,(debugfile,"mwoh: pfx=[%s], tag=[%s], flags=%d value=[%s]\n",
-           pfx, tag, flags, value));
+           NONULL (pfx), tag, flags, value));
 
   if (tag && *tag && fprintf (fp, "%s%s: ", NONULL (pfx), tag) < 0)
     return -1;