test: remove flaky designation from ls-no-sslv3

This test was marked flaky after failing in CI on arm7-wheezy two months
ago. It has not failed there since. This commit removes the flaky
designation.

Fixes: #2554
PR-URL: #3620
Reviewed-By: Johan Bergström <bugs@bergstroem.nu>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>

Author: Trott

test/parallel/parallel.status

@@ -12,7 +12,6 @@ test-child-process-fork-regr-gh-2847 : PASS,FLAKY
 
 [$system==linux]
 test-http-client-timeout-event    : PASS,FLAKY
-test-tls-no-sslv3                 : PASS,FLAKY
 test-child-process-buffering      : PASS,FLAKY
 test-child-process-exit-code      : PASS,FLAKY