[vala] Set libxml2 method accepting nullable

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit a1afb5aad3eb718d7dd14c35d6b786a4bd2b7689
Author: Daniel Espinosa <daniel espinosa pwmc mx>
Date:   Wed Mar 1 10:47:54 2017 -0600

    Set libxml2 method accepting nullable

 vapi/libxml-2.0.vapi |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/vapi/libxml-2.0.vapi b/vapi/libxml-2.0.vapi
index a4e62c8..7d0c338 100644
--- a/vapi/libxml-2.0.vapi
+++ b/vapi/libxml-2.0.vapi
@@ -812,7 +812,7 @@ namespace Xml {
                public Attr* set_ns_prop (Ns* ns, [CCode (type = "xmlChar*")] string name, [CCode (type = 
"xmlChar*")] string value);
 
                [CCode (cname = "xmlSetProp")]
-               public Attr* set_prop ([CCode (type = "xmlChar*")] string name, [CCode (type = "xmlChar*")] 
string value);
+               public Attr* set_prop ([CCode (type = "xmlChar*")] string name, [CCode (type = "xmlChar*")] 
string? value);
 
                [CCode (cname = "xmlSetTreeDoc")]
                public void set_tree_doc (Doc* doc);
@@ -1103,7 +1103,7 @@ namespace Xml {
                public int start_element ([CCode (type = "xmlChar*")] string name);
 
                [CCode (cname = "xmlTextWriterStartElementNS")]
-               public int start_element_ns ([CCode (type = "xmlChar*")] string prefix, [CCode (type = 
"xmlChar*")] string name, [CCode (type = "xmlChar*")] string namespaceURI);
+               public int start_element_ns ([CCode (type = "xmlChar*")] string prefix, [CCode (type = 
"xmlChar*")] string name, [CCode (type = "xmlChar*")] string? namespaceURI);
 
                [CCode (cname = "xmlTextWriterStartAttribute")]
                public int start_attribute ([CCode (type = "xmlChar*")] string name);