msxml3: Don't leak externaly allocated xmlSAXHandler.

dlls/msxml3/saxreader.c

diff --git a/dlls/msxml3/saxreader.c b/dlls/msxml3/saxreader.c
index 90600eb..6cf95d1 100644
--- a/dlls/msxml3/saxreader.c
+++ b/dlls/msxml3/saxreader.c
@@ -1787,6 +1787,7 @@
         return E_FAIL;
     }
 
+    xmlFree(locator->pParserCtxt->sax);
     locator->pParserCtxt->sax = &locator->saxreader->sax;
     locator->pParserCtxt->userData = locator;