NO-JIRA: [ruby] Fix race condition in container tests.
NO-JIRA: [ruby] Fix race condition in container tests.

apache/qpid-proton,ssorj/qpid-proton,apache/qpid-proton,kgiusti/qpid-proton,ssorj/qpid-proton,gemmellr/qpid-proton,alanconway/qpid-proton,alanconway/qpid-proton,ChugR/qpid-proton,gemmellr/qpid-proton,ChugR/qpid-proton,ChugR/qpid-proton,astitcher/qpid-proton,gemmellr/qpid-proton,apache/qpid-proton,alanconway/qpid-proton,ChugR/qpid-proton,astitcher/qpid-proton,alanconway/qpid-proton,astitcher/qpid-proton,alanconway/qpid-proton,kgiusti/qpid-proton,astitcher/qpid-proton,ChugR/qpid-proton,kgiusti/qpid-proton,ssorj/qpid-proton,alanconway/qpid-proton,ssorj/qpid-proton,astitcher/qpid-proton,kgiusti/qpid-proton,kgiusti/qpid-proton,gemmellr/qpid-proton,kgiusti/qpid-proton,apache/qpid-proton,gemmellr/qpid-proton,gemmellr/qpid-proton,ChugR/qpid-proton,astitcher/qpid-proton,ssorj/qpid-proton,ssorj/qpid-proton,apache/qpid-proton,apache/qpid-proton