Switch default db host to 127.0.0.1

This reverts octobercms/october@1ec2b69 (bringing back octobercms/october@6c5a83d) as it is more important for the default configuration to be in a working state for most environments than to optimize for performance for some environments. Having the default be `localhost` has caused issues for a large number of people (see octobercms/october#3411, #157, and probably many more). 

Additionally, this has been the default in Laravel since 5.2 (laravel/laravel#3641) & 5.3 (laravel/laravel@fd42e10).

Author: LukeTowers

config/database.php

@@ -55,7 +55,7 @@
         'mysql' => [
             'driver'     => 'mysql',
             'engine'     => 'InnoDB',
-            'host'       => 'localhost',
+            'host'       => '127.0.0.1',
             'port'       => 3306,
             'database'   => 'database',
             'username'   => 'root',
@@ -68,7 +68,7 @@
 
         'pgsql' => [
             'driver'   => 'pgsql',
-            'host'     => 'localhost',
+            'host'     => '127.0.0.1',
             'port'     => 5432,
             'database' => 'database',
             'username' => 'root',
@@ -80,7 +80,7 @@
 
         'sqlsrv' => [
             'driver'   => 'sqlsrv',
-            'host'     => 'localhost',
+            'host'     => '127.0.0.1',
             'port'     => 1433,
             'database' => 'database',
             'username' => 'root',