Support building on ruby 1.8 again, last commit broke ruby 1.8 version.

Noticed by naddy@

databases/ruby-mysql/patches/patch-ext_mysql_api_mysql_c

@@ -1,18 +1,22 @@
-$OpenBSD: patch-ext_mysql_api_mysql_c,v 1.1 2017/01/06 15:55:38 jeremy Exp $
+$OpenBSD: patch-ext_mysql_api_mysql_c,v 1.2 2017/01/07 18:09:28 jeremy Exp $
 
 Allow building with ruby 2.4+.
 
 --- ext/mysql_api/mysql.c.orig	Wed Dec 31 16:00:00 1969
-+++ ext/mysql_api/mysql.c	Tue Oct 18 14:23:24 2016
-@@ -3,6 +3,7 @@
++++ ext/mysql_api/mysql.c	Sat Jan  7 10:06:36 2017
+@@ -3,6 +3,11 @@
   */
  
  #include <ruby.h>
++#ifdef HAVE_RUBY_ENCODING_H
 +#include <ruby/version.h>
++#else
++#define RUBY_API_VERSION_CODE 10807
++#endif
  #ifndef RSTRING_PTR
  #define RSTRING_PTR(str) RSTRING(str)->ptr
  #endif
-@@ -1317,7 +1318,11 @@ static VALUE stmt_bind_result(int argc, VALUE *argv, V
+@@ -1317,7 +1322,11 @@ static VALUE stmt_bind_result(int argc, VALUE *argv, V
  	}
  	else if (argv[i] == rb_cString)
  	    s->result.bind[i].buffer_type = MYSQL_TYPE_STRING;