Update .env

Author: chendelin1982

apps/opengauss/.env

@@ -8,7 +8,7 @@ W9_DB_PORT_SET=9056
 W9_ID='opengauss'
 
 # omm is root user, and $GS_USERNAME is extra test user
-W9_LOGIN_USER=omm
+W9_LOGIN_USER=gaussdb
 W9_LOGIN_PASSWORD=$W9_POWER_PASSWORD
 W9_NETWORK=websoft9