Fix the testsuite when the OS locale is not English
Fix the testsuite when the OS locale is not English

The environment is inherited in subprocesses, so the LANG variable
should be reset to be sure that the default language is English when
running Behat in the scenarios.

Behat/Behat,spolischook/behat,Taluu/Behat,spolischook/behat,v-abramchuk/Behat,spolischook/behat