Revert "Issue #2427875 by daffie: SQLite Insert query does not account for INSERT FROM ... SELECT"

This reverts commit d1a9a099.

core/lib/Drupal/Core/Database/Driver/sqlite/Insert.php

@@ -22,7 +22,7 @@ public function execute() {
     if (!$this->preExecute()) {
       return NULL;
     }
-    if (count($this->insertFields) || !empty($this->fromQuery)) {
+    if (count($this->insertFields)) {
       return parent::execute();
     }
     else {
@@ -35,10 +35,7 @@ public function __toString() {
     $comments = $this->connection->makeComment($this->comments);
 
     // Produce as many generic placeholders as necessary.
-    $placeholders = array();
-    if (!empty($this->insertFields)) {
-      $placeholders = array_fill(0, count($this->insertFields), '?');
-    }
+    $placeholders = array_fill(0, count($this->insertFields), '?');
 
     // If we're selecting from a SelectQuery, finish building the query and
     // pass it back, as any remaining options are irrelevant.