Merge pull request #22672 from kevinmeredith/correct_trapped_signals

Correct docs for a docker container's clean-up.
(cherry picked from commit c273163e80da5f5895db1dc1102a470ec45e0a69)

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

docs/reference/builder.md

@@ -834,7 +834,7 @@ does some more work:
 
 # USE the trap if you need to also do manual cleanup after the service is stopped,
 #     or need to start multiple services in the one container
-trap "echo TRAPed signal" HUP INT QUIT KILL TERM
+trap "echo TRAPed signal" HUP INT QUIT TERM
 
 # start service in background here
 /usr/sbin/apachectl start