NullPointer when starting a multi machine workspace

[ghost]

If a workspace contains more than one machine, workspace creation and boot fails

Reproduction Steps:

1. Create a workspace with the following custom recipe:

services:
 machine:
  image: codenvy/ubuntu_jdk8
  mem_limit: 2147483648
 dev-machine:
  image: codenvy/ubuntu_jdk8
  mem_limit: 2147483648
  depends_on:
    - machine

Client error:

Server logs:

2016-09-13 09:33:08,458[kspaceManager-0]  [ERROR] [o.e.c.a.w.s.WorkspaceManager 665]    - Start of environment wksp-afyi failed. Error: null
org.eclipse.che.api.core.ServerException: Start of environment wksp-afyi failed. Error: null
    at org.eclipse.che.api.workspace.server.WorkspaceRuntimes.start(WorkspaceRuntimes.java:277) ~[che-core-api-workspace-5.0.0-M1-SNAPSHOT.jar:5.0.0-M1-SNAPSHOT]
    at org.eclipse.che.api.workspace.server.WorkspaceManager.lambda$performAsyncStart$1(WorkspaceManager.java:649) ~[che-core-api-workspace-5.0.0-M1-SNAPSHOT.jar:5.0.0-M1-SNAPSHOT]
    at org.eclipse.che.api.workspace.server.WorkspaceManager$$Lambda$94/2096118671.run(Unknown Source) [che-core-api-workspace-5.0.0-M1-SNAPSHOT.jar:5.0.0-M1-SNAPSHOT]
    at org.eclipse.che.commons.lang.concurrent.CopyThreadLocalRunnable.run(CopyThreadLocalRunnable.java:28) [che-core-commons-lang-5.0.0-M1-SNAPSHOT.jar:5.0.0-M1-SNAPSHOT]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_31]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_31]
    at java.lang.Thread.run(Thread.java:745) [na:1.8.0_31]
Caused by: java.lang.NullPointerException: null
    at org.eclipse.che.api.environment.server.CheEnvironmentEngine.applyAgents(CheEnvironmentEngine.java:517) ~[che-core-api-workspace-5.0.0-M1-SNAPSHOT.jar:5.0.0-M1-SNAPSHOT]
    at org.eclipse.che.api.environment.server.CheEnvironmentEngine.initializeEnvironment(CheEnvironmentEngine.java:492) ~[che-core-api-workspace-5.0.0-M1-SNAPSHOT.jar:5.0.0-M1-SNAPSHOT]
    at org.eclipse.che.api.environment.server.CheEnvironmentEngine.start(CheEnvironmentEngine.java:213) ~[che-core-api-workspace-5.0.0-M1-SNAPSHOT.jar:5.0.0-M1-SNAPSHOT]
    at org.eclipse.che.api.workspace.server.WorkspaceRuntimes.start(WorkspaceRuntimes.java:246) ~[che-core-api-workspace-5.0.0-M1-SNAPSHOT.jar:5.0.0-M1-SNAPSHOT]
    ... 6 common frames omitted