updated for version 7.3.711

Problem:    vim.current.buffer is not available. (lilydjwg)
Solution:   Use py3_PyUnicode_AsUTF8 instead of py3_PyUnicode_AsUTF8String.
            (Ken Takata)

src/version.c

@@ -725,6 +725,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    711,
 /**/
     710,
 /**/