patch 8.0.0709: libvterm cannot use vsnprintf()

Problem:    Libvterm cannot use vsnprintf(), it does not exist in C90.
Solution:   Use vim_vsnprintf() instead.
diff --git a/src/netbeans.c b/src/netbeans.c
index fb4cb76..93563b1 100644
--- a/src/netbeans.c
+++ b/src/netbeans.c
@@ -2301,7 +2301,7 @@
     va_list ap;
 
     va_start(ap, cmd);
-    vim_vsnprintf(buf, sizeof(buf), cmd, ap, NULL);
+    vim_vsnprintf(buf, sizeof(buf), cmd, ap);
     va_end(ap);
 
     nbdebug(("    COLONCMD %s\n", buf));