Database configuration doesn't work

[masm]

After looking how a redis connection is setup on environment.js, I've tried to the following change to configure a different host for redis:

diff --git a/config/database.js b/config/database.js
index e0003f1..9d70faa 100644
--- a/config/database.js
+++ b/config/database.js
@@ -1,4 +1,4 @@
-module.exports = 
+module.exports =
   { "development":
     { "driver":   "redis-hq"
     , "prefix":   "dev"
@@ -6,7 +6,7 @@ module.exports =
     , "fulltext": {
         driver: 'reds'
     }
-    , "session": {database: 10}
+    , "session": {database: 10, host: "redis"}
     }
   , "test":
     { "driver":   "redis-hq"

but I still get a connection error with

UncaughtException: Redis connection to 127.0.0.1:6379 failed - connect ECONNREFUSED

How do I configure a different host? The docs mention that I need to change that file.