575875 don't output charset=html

* HTMLtree.c: don't output charset=html in htmlSetMetaEncoding()
  as this is clearly a libxml2 only thingused for import only
diff --git a/HTMLtree.c b/HTMLtree.c
index 37999f7..d55ff28 100644
--- a/HTMLtree.c
+++ b/HTMLtree.c
@@ -168,6 +168,10 @@
     if (doc == NULL)
 	return(-1);
 
+    /* html isn't a real encoding it's just libxml2 way to get entities */
+    if (!xmlStrcasecmp(encoding, BAD_CAST "html"))
+        return(-1);
+
     if (encoding != NULL) {
 	snprintf(newcontent, sizeof(newcontent), "text/html; charset=%s",
                 (char *)encoding);