MINOR Tweak text about display_errors

dev/install/install.php5

@@ -405,7 +405,7 @@ class InstallRequirements {
 
 		$this->suggestPHPSetting('asp_tags', array(''), array('PHP Configuration', 'asp_tags option turned off', 'This should be turned off as it can cause issues with SilverStripe'));
 		$this->suggestPHPSetting('magic_quotes_gpc', array(''), array('PHP Configuration', 'magic_quotes_gpc option turned off', 'This should be turned off, as it can cause issues with cookies. More specifically, unserializing data stored in cookies.'));
-		$this->suggestPHPSetting('display_errors', array(''), array('PHP Configuration', 'display_errors option turned off', 'This should be turned off, as it can expose sensitive data to website users.'));
+		$this->suggestPHPSetting('display_errors', array(''), array('PHP Configuration', 'display_errors option turned off', 'Unless you\'re in a development environment, this should be turned off, as it can expose sensitive data to website users.'));
 
 		// Check memory allocation
 		$this->requireMemory(32*1024*1024, 64*1024*1024, array("PHP Configuration", "Memory allocated (PHP config option 'memory_limit')", "SilverStripe needs a minimum of 32M allocated to PHP, but recommends 64M.", ini_get("memory_limit")));