software/slapos-sr-testing: run nginx-push-stream only on python3

Now that slapos.core on python2 can use softwares on python3, we no
longer need to test for python2

software/slapos-sr-testing/software-py3.cfg

@@ -17,6 +17,7 @@ extra =
   helloworld ${slapos.test.helloworld-setup:setup}
   jupyter ${slapos.test.jupyter-setup:setup}
   monitor ${slapos.test.monitor-setup:setup}
+  nginx-push-stream ${slapos.test.nginx-push-stream-setup:setup}
   plantuml ${slapos.test.plantuml-setup:setup}
   powerdns ${slapos.test.powerdns-setup:setup}
   proftpd ${slapos.test.proftpd-setup:setup}

software/slapos-sr-testing/software.cfg

@@ -338,7 +338,6 @@ tests =
   slaprunner ${slapos.test.slaprunner-setup:setup}
   theia ${slapos.test.theia-setup:setup}
   metabase ${slapos.test.metabase-setup:setup}
-  nginx-push-stream ${slapos.test.nginx-push-stream-setup:setup}
   erp5 ${slapos.test.erp5-setup:setup}
 ###
   ${:extra}