patch 9.1.0195: memleak with ex_drop, NULL dereference

Problem:  memleak with ex_drop(), NULL dereference
          (zeertzjq)
Solution: revert back to ex_rewind(), use curbuf instead of buf

fixes: #14246
closes: #14251

Signed-off-by: Christian Brabandt <cb@256bit.org>

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    195,
 /**/
     194,
 /**/