gitlab CI: stop requiring Signed-off-by in commits

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>

.gitlab-ci.yml

@@ -35,14 +35,14 @@ variables:
 
 
 #
-# Verify that commit messages are as expected, signed-off, etc.
+# Verify that commit messages are as expected
 #
 check-commits:
   extends:
     - .fdo.ci-fairy
   stage: prep
   script:
-    - ci-fairy check-commits --signed-off-by --junit-xml=results.xml
+    - ci-fairy check-commits --junit-xml=results.xml
   except:
     - master@xorg/driver/xf86-video-nv
   variables: