fix following freetds update, which moved DBMAXNAME defn to a non-installed

header. spotted by nigel@, https://github.com/FreeTDS/freetds/issues/57

databases/p5-sybperl/patches/patch-DBlib_DBlib_xs

@@ -0,0 +1,19 @@
+$OpenBSD: patch-DBlib_DBlib_xs,v 1.3 2016/03/28 11:17:06 sthen Exp $
+
+https://github.com/FreeTDS/freetds/issues/57
+
+--- DBlib/DBlib.xs.orig	Mon Mar 28 12:07:31 2016
++++ DBlib/DBlib.xs	Mon Mar 28 12:12:02 2016
+@@ -137,7 +137,11 @@ typedef struct daterec
+ #endif /* DBLIBVS < 1000 */
+ 
+ #if !defined(DBMAXNAME)
+-#define DBMAXNAME          MAXNAME
++/*
++ * https://msdn.microsoft.com/en-us/library/ms176061.aspx
++ * https://github.com/FreeTDS/freetds/commit/a19a535e80542d6a26473f748c0d5aa21f8c4233
++ */
++#define DBMAXNAME   128
+ #endif
+ 
+ typedef enum hash_key_id