Upgrade reactivemongo 0.12.2 -> 0.12.3

Upgrading to 0.12.7 resulted to disastrous disk reads on the primary.
Now upgrading one version at a time to identify the culprit

modules/db/src/main/CollExt.scala

@@ -145,18 +145,19 @@ trait CollExt { self: dsl with QueryBuilderExt =>
       maxDocs: Int,
       readPreference: ReadPreference = ReadPreference.primary,
       allowDiskUse: Boolean = false
-    ): Fu[List[Bdoc]] = coll.aggregate1[Bdoc](
+    ): Fu[List[Bdoc]] = coll.aggregatorContext[Bdoc](
       firstOperator,
       otherOperators,
       readPreference = readPreference
-    ).collect[List](maxDocs = maxDocs, Cursor.FailOnError[List[Bdoc]]())
+    ).prepared[Cursor](CursorProducer.defaultCursorProducer[Bdoc]).cursor.collect[List](maxDocs = maxDocs, Cursor.FailOnError[List[Bdoc]]())
 
     def aggregateOne(
       firstOperator: AggregationFramework.PipelineOperator,
       otherOperators: List[AggregationFramework.PipelineOperator] = Nil,
       readPreference: ReadPreference = ReadPreference.primary
     ): Fu[Option[Bdoc]] =
-      coll.aggregate1[Bdoc](firstOperator, otherOperators, readPreference = readPreference).headOption
+      coll.aggregatorContext[Bdoc](firstOperator, otherOperators, readPreference = readPreference)
+        .prepared[Cursor](CursorProducer.defaultCursorProducer[Bdoc]).cursor.headOption
 
     def distinctWithReadPreference[T, M[_] <: Iterable[_]](
       key: String,

modules/learn/src/main/BSONHandlers.scala

@@ -1,6 +1,6 @@
 package lila.learn
 
-import reactivemongo.bson._
+import reactivemongo.bson.{ MapReader => _, MapWriter => _, _ }
 
 import lila.db.BSON
 import lila.db.dsl._

modules/lobby/src/main/Seek.scala

@@ -102,7 +102,7 @@ object Seek {
     createdAt = DateTime.now
   )
 
-  import reactivemongo.bson._
+  import reactivemongo.bson.{ MapReader => _, MapWriter => _, _ }
   import lila.db.BSON.MapValue.MapHandler
   import lila.db.BSON.BSONJodaDateTimeHandler
   implicit val lobbyPerfBSONHandler = new BSONHandler[BSONInteger, LobbyPerf] {

project/Dependencies.scala

@@ -44,7 +44,7 @@ object Dependencies {
   val jwt = "com.pauldijou" %% "jwt-core" % "0.14.1"
 
   object reactivemongo {
-    val version = "0.12.2"
+    val version = "0.12.3"
     val driver = ("org.reactivemongo" %% "reactivemongo" % version)
       .exclude("com.typesafe.akka", "*") // provided by Play
       .exclude("com.typesafe.play", "*")