[NDB_BVL_Instrument] Fix for clearing instrument (aces#9411)

Ignore commentID when clearing instrument.

When running clear instrument on a non JSON instrument the commentID
primary key is non-nullable, which it tries to set values to null which results in an
error, this is resolved.

Ignore CommentID when clearing.

php/libraries/NDB_BVL_Instrument.class.inc

@@ -2644,7 +2644,7 @@ abstract class NDB_BVL_Instrument extends NDB_Page
         if (!$this->jsonData) {
             $columns = $db->pselect(
                 "SELECT COLUMN_NAME FROM information_schema.columns
-            WHERE TABLE_NAME=:table AND TABLE_SCHEMA=:db",
+            WHERE COLUMN_NAME<>'CommentID' AND TABLE_NAME=:table AND TABLE_SCHEMA=:db",
                 [
                     'table' => $this->table,
                     'db'    => $dbconfig['database'],