Try clicking only

Moving mouse seems to be problematic in Selenium, see
https://code.google.com/p/selenium/issues/detail?id=2067

Signed-off-by: Michal Čihař <michal@cihar.com>

test/selenium/TestBase.php

@@ -431,7 +431,6 @@ abstract class PMA_SeleniumBase extends PHPUnit_Extensions_Selenium2TestCase
         } catch (PHPUnit_Extensions_Selenium2TestCase_WebDriverException $e) {
             return;
         }
-        $this->moveto($more);
         $more->click();
     }
 }