JENKINS-64946 : Branch indexing occurring for every multibranch job

execution

WHAT

1. If multibranch project trigger a build for a branch then it should
build for head which is in the Observer and not for all heads that
matches the multibranch.

src/test/java/org/jenkinsci/plugins/p4/DefaultEnvironment.java

@@ -236,7 +236,7 @@ protected void commitFile(JenkinsRule jenkins, String path, String content) thro
 	}
 
 	protected boolean waitForBuild(WorkflowJob job, int buildNumber) throws InterruptedException {
-		return waitForBuild(job, buildNumber, 50, 200L);
+		return waitForBuild(job, buildNumber, 170, 200L);
 	}
 
 	protected boolean waitForBuild(WorkflowJob job, int buildNumber, final int retry, long delay) throws InterruptedException {