[gegl] bin: guard mrg code in argvs with ifdefs

[Øyvind "pippin" Kolås <ok src gnome org>]

commit be9f6e59014ef15f429a42d26faadc672894b275
Author: Øyvind Kolås <pippin gimp org>
Date:   Wed Jan 16 17:04:36 2019 +0100

    bin: guard mrg code in argvs with ifdefs

 bin/argvs.c | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/bin/argvs.c b/bin/argvs.c
index 49026ba02..73d8c9fc8 100644
--- a/bin/argvs.c
+++ b/bin/argvs.c
@@ -10,6 +10,8 @@
  * advacned behavior.
  */
 
+#include "config.h"
+
 #include <stdio.h>
 
 #include <stdlib.h>
@@ -17,7 +19,11 @@
 #include <unistd.h>
 #include "argvs.h"
 
+#if HAVE_MRG
 #define MRG_PRINTF 1
+#endif
+
+
 #ifdef MRG_PRINTF
 #include <mrg.h>
 #include <mrg-string.h>