Helper_Data#isModuleEnabled crashes the adminhtml

[Hanmac]

https://github.com/mollie/Magento/blob/e3e85896d98aa362fd349841f160722a23e6a3de/app/code/community/Mollie/Mpm/Helper/Data.php#L85-L96

crashes the adminhtml, see this Stacktrace:

Mage_Core_Model_Store_Exception in /var/www/bauma1.9.x/app/code/core/Mage/Core/Model/App.php:1484
Stack trace:
#0 /var/www/app/code/core/Mage/Core/Model/App.php(882): Mage_Core_Model_App->throwStoreException()
#1 /var/www/app/Mage.php(411): Mage_Core_Model_App->getStore('Mollie_Mpm')
#2 /var/www/vendor/mollie/magento/app/code/community/Mollie/Mpm/Helper/Data.php(132): Mage::getStoreConfig('payment/mollie/...', 'Mollie_Mpm')
#3 /var/www/vendor/mollie/magento/app/code/community/Mollie/Mpm/Helper/Data.php(107): Mollie_Mpm_Helper_Data->getStoreConfig('payment/mollie/...', 'Mollie_Mpm')
#4 /var/www/vendor/mollie/magento/app/code/community/Mollie/Mpm/Helper/Data.php(95): Mollie_Mpm_Helper_Data->isAvailable('Mollie_Mpm')
#5 /var/www/app/code/core/Mage/Core/Helper/Abstract.php(134): Mollie_Mpm_Helper_Data->isModuleEnabled('Mollie_Mpm')
#6 /var/www/app/code/core/Mage/Adminhtml/Block/Page/Menu.php(307): Mage_Core_Helper_Abstract->isModuleOutputEnabled()
#7 /var/www/app/code/core/Mage/Adminhtml/Block/Page/Menu.php(127): Mage_Adminhtml_Block_Page_Menu->_isEnabledModuleOutput(Object(Varien_Simplexml_Element))
#8 /var/www/app/code/core/Mage/Adminhtml/Block/Page/Menu.php(88): Mage_Adminhtml_Block_Page_Menu->_buildMenuArray(Object(Varien_Simplexml_Element))

Because the Adminhtml refers to mpm: <mollie module="mpm">, the Menu class is looking if the Module is Enabled or not

The Original Method uses $moduleName and not $storeId = null

public function isModuleEnabled($moduleName = null)