Pass LANG variable to msgfilter in crowdin script

.ci/Jenkinsfile.crowdin

@@ -38,7 +38,7 @@ timestamps {
             sh "$crowdin_cli download --branch ${upstream_branch}"
           }
         }
-        sh 'find . -name "*.po" -exec msgfilter -i "{}" -o "{}.replacement" .ci/cleanup-po.pl ";"'
+        sh 'LANG=en_US.utf8 find . -name "*.po" -exec msgfilter -i "{}" -o "{}.replacement" .ci/cleanup-po.pl ";"'
         sh 'find . -name "*.po" -exec mv "{}.replacement" "{}" ";"'
       }
       stage('Push') {