Do not throw an exception in DbTool due to an implementation detail

Throwing exceptions due to failing logic which is purely an implementation
detail must not affect the calling code in any way.

refs #7163

library/Icinga/Web/Setup/DbTool.php

@@ -4,7 +4,6 @@
 
 namespace Icinga\Web\Setup;
 
-use Icinga\Exception\ProgrammingError;
 use PDO;
 use PDOException;
 use LogicException;
@@ -66,7 +65,6 @@ public function connectToHost()
             // Therefore, we specify the maintenance database 'postgres' as database, which
             // is most probably present and public.
             $this->connect('postgres');
-
         } else {
             $this->connect();
         }
@@ -387,13 +385,11 @@ public function listTables()
      * Return whether the given database login exists
      *
      * @param   string  $username   The username to search
-     * @param   string  $password   The username to login
+     * @param   string  $password   The password for user $username, required in case it's a MySQL database
      *
      * @return  bool
-     * @throws  PDOException        When logging in is not possible due to an Exception not related
-     *                              to authentication
      */
-    public function hasLogin($username, $password)
+    public function hasLogin($username, $password = null)
     {
         if ($this->config['db'] === 'mysql') {
             // probe login by trial and error since we don't know our host name or it may be globbed
@@ -404,12 +400,9 @@ public function hasLogin($username, $password)
                 $probe = new DbTool($probeConf);
                 $probe->connectToHost();
             } catch (PDOException $e) {
-                $code = $e->getCode();
-                if ($code === 1045 || $code === 1044) {
-                    return false;
-                }
-                throw $e;
+                return false;
             }
+
             return true;
         } elseif ($this->config['db'] === 'pgsql') {
             $rowCount = $this->exec(