patch 8.1.0119: failing test goes unnoticed because messages is not written

Problem:    Failing test goes unnoticed because testdir/messages is not
            written.
Solution:   Set 'nomodifiable' only local to the buffer.

src/version.c

@@ -789,6 +789,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    119,
 /**/
     118,
 /**/