Revert "Abstracting the loading of files in the config directory depending on environments."

This reverts commit 5c1aa631c5f5ec2f6b75ba1158178418e50ba11a.
diff --git a/system/libraries/User_agent.php b/system/libraries/User_agent.php
index 5288525..c31ff26 100644
--- a/system/libraries/User_agent.php
+++ b/system/libraries/User_agent.php
@@ -94,10 +94,15 @@
 	 */
 	protected function _load_agent_file()
 	{
-		load_environ_config('user_agents');
-
-		// Return FALSE if we still have no mimes after trying to load them up.
-		if (count($this->mimes) === 0)
+		if (defined('ENVIRONMENT') AND is_file(APPPATH.'config/'.ENVIRONMENT.'/user_agents.php'))
+		{
+			include(APPPATH.'config/'.ENVIRONMENT.'/user_agents.php');
+		}
+		elseif (is_file(APPPATH.'config/user_agents.php'))
+		{
+			include(APPPATH.'config/user_agents.php');
+		}
+		else
 		{
 			return FALSE;
 		}