Add default value for CI env

issue10455
review332961002

tox.ini

@@ -13,4 +13,4 @@ setenv =
     sqlite: DB_NAME={env:SQLITE_NAME::memory:}
     postgresql: DB_NAME={env:POSTGRESQL_NAME:test}
 passenv=DPD_USER_ID DPD_PASSWORD
-install_command = pip install --pre --find-links https://trydevpi.tryton.org/?local_version={env:CI_JOB_ID:{env:CI_BUILD_NUMBER}.{env:CI_JOB_NUMBER}} {opts} {packages}
+install_command = pip install --pre --find-links https://trydevpi.tryton.org/?local_version={env:CI_JOB_ID:{env:CI_BUILD_NUMBER:}.{env:CI_JOB_NUMBER:}} {opts} {packages}