patch 9.1.0126: Internal error when using upper-case mark in getregion()

Problem:  Internal error when passing mark in another buffer to
          getregion().
Solution: Don't allow marks in another buffer (zeertzjq)

closes: #14076

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Internal error when passing mark in another buffer to getregion()

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    126,
 /**/
     125,
 /**/