fix logger check

share/github-backup-utils/ghe-restore-audit-log

@@ -42,8 +42,7 @@ mysql_table_schema_available(){
 # Check whether the remote host is running a version where the MySQL backend
 # is supported, i.e: < 2.19
 is_mysql_supported(){
-  ghe-ssh "$GHE_HOSTNAME" sudo grep -q "ENTERPRISE_AUDIT_LOG_MYSQL_LOGGER_ENABLED='1'" \
-    /data/github/current/.app-config/env.d/99-instance.sh
+  ghe-ssh "$GHE_HOSTNAME" "sudo grep \"ENTERPRISE_AUDIT_LOG_MYSQL_LOGGER_ENABLED='1'\" /data/github/current/.app-config/env.d/99-instance.sh"
 }
 
 # Helper function to set remote flags in `/data/user/common/audit-log-import`