scheduler: Make 'https://' optional in 'server' config field.

scheduler/appengine/task/buildbucket/buildbucket_test.go

 // Copyright 2015 The LUCI Authors.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //      http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 28 matching lines @@
                         Server:     "https://blah.com",
                         Bucket:     "bucket",
                         Builder:    "builder",
                         Tags:       []string{"a:b", "c:d"},
                         Properties: []string{"a:b", "c:d"},
                 }), ShouldBeNil)
         })
 
         Convey("ValidateProtoMessage passes good minimal msg", t, func() {
                 So(tm.ValidateProtoMessage(&messages.BuildbucketTask{
-                        Server:  "https://blah.com",
+                        Server:  "blah.com",
                         Bucket:  "bucket",
                         Builder: "builder",
                 }), ShouldBeNil)
         })
 
         Convey("ValidateProtoMessage wrong type", t, func() {
                 So(tm.ValidateProtoMessage(&messages.NoopTask{}), ShouldErrLike, "wrong type")
         })
 
         Convey("ValidateProtoMessage empty", t, func() {
                 So(tm.ValidateProtoMessage(tm.ProtoMessageType()), ShouldErrLike, "expecting a non-empty BuildbucketTask")
         })
 
         Convey("ValidateProtoMessage validates URL", t, func() {
                 call := func(url string) error {
                         return tm.ValidateProtoMessage(&messages.BuildbucketTask{
                                 Server:  url,
                                 Bucket:  "bucket",
                                 Builder: "builder",
                         })
                 }
                 So(call(""), ShouldErrLike, "field 'server' is required")
                 So(call("%%%%"), ShouldErrLike, "invalid URL")
-                So(call("/abc"), ShouldErrLike, "not an absolute url")
+                So(call("/abc"), ShouldErrLike, "not a host root url")
                 So(call("https://host/not-root"), ShouldErrLike, "not a host root url")
         })
 
         Convey("ValidateProtoMessage needs bucket", t, func() {
                 So(tm.ValidateProtoMessage(&messages.BuildbucketTask{
                         Server:  "https://blah.com",
                         Builder: "builder",
                 }), ShouldErrLike, "'bucket' field is required")
         })
 
@@ skipping 118 matching lines @@
                                 Name:  statusCheckTimerName,
                         },
                 })
 
                 // Process finish notification.
                 mockRunning = false
                 So(mgr.HandleNotification(c, ctl, &pubsub.PubsubMessage{}), ShouldBeNil)
                 So(ctl.TaskState.Status, ShouldEqual, task.StatusSucceeded)
         })
 }