How can I hide a certain warning message showing to users? I would like to hide the following warning message from users when they submit a web form. I know when this warning message shows up and don't really need to fix it but just want to hide it from users.

warning: trim() expects parameter 1 to be string, array given in /public_html/sites/all/modules/phpmailer/includes/phpmailer.drupal.inc on line 33.


I tried Disable message module but it's only for the Drupal system error message.
Is there anyway to hide a certain warning message just like above?
You need to include ini_set( 'display_errors','0'); in your setting.php file in drupal site.

See more about error reporting 
http://php.net/manual/en/function.error-reporting.php 

// Reporting E_NOTICE can be good too (to report uninitialized
// variables or catch variable name misspellings ...)

ini_set( 'display_errors','0');