Update MNCC field validation mask.

In c6921e5068ba62cde67707fb3c8103919d1e0c0e, 0x4000 was added to the
possible MNCC field flags, but before this commit, using it would
result in an ERROR of "Unknown MNCC field mask 0x....."

Related: OS#5282
Change-Id: I9e7d224e7f2d6d2824b2466752b6e8c994ac5a3d
diff --git a/src/libmsc/mncc.c b/src/libmsc/mncc.c
index 0a38997..f446f98 100644
--- a/src/libmsc/mncc.c
+++ b/src/libmsc/mncc.c
@@ -110,7 +110,7 @@
  * MNCC validation code. Move to libosmocore once headers are merged
  ************************************************************************/
 
-#define MNCC_F_ALL 0x3fff
+#define MNCC_F_ALL 0x7fff
 
 static int check_string_terminated(const char *str, unsigned int size)
 {