Merge pull request #1079 from mulesoft/Fix-flaky-test-CloseStreamOnMuleExceptionTestCase

removing thread.sleep for polling prober
(cherry picked from commit 08a37da8ca9eace1c21ddc0a27749608d863de1d)

(cherry picked from commit edbb5763849c05310a390e8726146d95105305af)
(cherry picked from commit 5e2380a7173e665c5147e7c77c3027b3542c59b4)