patch 8.1.0944: format of nbdbg() arguments is not checked

Problem:    Format of nbdbg() arguments is not checked.
Solution:   Add format attribute.  Fix reported problems. (Dominique Pelle,
            closes #3992)

src/version.c

@@ -779,6 +779,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    944,
 /**/
     943,
 /**/