Fix 'useradd' when user is already (e.g, ubuntu)

The fix assume 'useradd' fails only in this case.

Author: Carlos Brandt

entrypoint.sh

@@ -42,7 +42,7 @@ function config_user()
             -g "$DGID" \
             -d "/home/$DUSER" -m \
             -s /bin/bash \
-            "$DUSER" || return 1
+            "$DUSER" || DUSER=$(id -u $DUID -n)
 
     echo "$DUSER"
     return 0