Prevent spurious bad version string warnings when upgrading from <=3.3

We still ended up with the correct version number anyways, but just killing the
warnings completely makes it less likely the end user will thing something's
gone wrong.
17 jobs for !169 with iss50-versions in 69 minutes and 16 seconds (queued for 34 minutes and 30 seconds)
Child pipeline (parent) detached
Status Name Job ID Coverage
  Build
passed Build ASDF #26560

00:01:06

passed Build docs #26561

00:04:04

 
  Regression
passed Regression test: [abcl, 1.7.1-jdk8] #26569

00:31:19

passed Regression test: [abcl, latest] #26562

00:32:44

passed Regression test: [ccl, latest] #26563

00:08:56

passed Regression test: [clasp, latest] #26564

00:38:48

passed Regression test: [clisp, latest] #26565

00:07:03

passed Regression test: [cmucl, latest] #26566

00:07:37

passed Regression test: [ecl, latest] #26567

00:07:34

passed Regression test: [sbcl, latest] #26568

00:06:09

 
  Upgrade
passed REQUIRE upgrade test: [ccl, latest] #26570

00:01:33

passed REQUIRE upgrade test: [clisp, latest] #26571

00:01:43

passed REQUIRE upgrade test: [ecl, latest] #26572

00:03:55

failed REQUIRE upgrade test known failure: [abcl] #26575
allowed to fail

00:06:32

failed REQUIRE upgrade test known failure: [clasp, latest] #26576
allowed to fail

00:09:34

failed REQUIRE upgrade test known failure: [cmucl] #26574
allowed to fail

00:01:45

passed REQUIRE upgrade test: [sbcl, latest] #26573

00:01:16

 
Name Stage Failure
failed
REQUIRE upgrade test known failure: [cmucl] Upgrade
No job log
failed
REQUIRE upgrade test known failure: [abcl] Upgrade
No job log
failed
REQUIRE upgrade test known failure: [clasp, latest] Upgrade
No job log