patch 8.0.0235: memory leak in diff mode

Problem:    Memory leak detected when running tests for diff mode.
Solution:   Free p_extra_free.

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    235,
 /**/
     234,
 /**/