test: Temporarily enable s390 run

Signed-off-by: Anatol Belski <ab@php.net>

Author: weltling

.travis.yml

@@ -77,7 +77,6 @@ jobs:
           if: type = cron
         - env: ENABLE_ZTS=1 ENABLE_DEBUG=1 SKIP_IO_CAPTURE_TESTS=1 S390X=1
           arch: s390x
-          if: type = cron
 
 before_script:
     - ccache --version