fix wrong collection name

Author: robkooper

app/services/mongodb/MongoSalatPlugin.scala

@@ -118,9 +118,9 @@ class MongoSalatPlugin(app: Application) extends Plugin {
     collection("collections").ensureIndex(MongoDBObject("author._id" -> 1))
     collection("collections").ensureIndex(MongoDBObject("stats" -> 1))
 
-    collection("collections").ensureIndex(MongoDBObject("file_id" -> 1))
-    collection("collections").ensureIndex(MongoDBObject("dataset_id" -> 1))
-    collection("collections").ensureIndex(MongoDBObject("comment_id" -> 1))
+    collection("comments").ensureIndex(MongoDBObject("file_id" -> 1))
+    collection("comments").ensureIndex(MongoDBObject("dataset_id" -> 1))
+    collection("comments").ensureIndex(MongoDBObject("comment_id" -> 1))
 
     collection("datasets").ensureIndex(MongoDBObject("created" -> -1))
     collection("datasets").ensureIndex(MongoDBObject("tags" -> 1))