System tests: unverbosify a flake log

One of our oldest most frustrating flakes is containers#16091, "Timed
out waiting for BYE".

In containers#17489 we added some debug output to see if the problem
was a container hang of some sort. It does not seem to be
(see containers#17675), and the debug output makes it hard to read
failure logs, so let's remove it.

Signed-off-by: Ed Santiago <santiago@redhat.com>

test/system/032-sig-proxy.bats

@@ -3,7 +3,7 @@
 load helpers
 
 # Command to run in each of the tests.
-SLEEPLOOP='trap "echo BYE;exit 0" INT;echo READY;while :;do echo RUNNING;sleep 0.1;done'
+SLEEPLOOP='trap "echo BYE;exit 0" INT;echo READY;while :;do sleep 0.1;done'
 
 function setup() {
     basic_setup