Update i_u_m_migration.md

- changed: lower-case mentions of mailcow

docs/i_u_m_migration.md

@@ -1,6 +1,6 @@
 #### Please note: This guide assumes you intend to migrate an existing mailcow server (source) over to a brand new, empty server (target). It takes no care about preserving any existing data on your target server and will erase anything within `/var/lib/docker/volumes` and thus any Docker volumes you may have already set up.
 
-##### Alternatively, you can use the `./helper-scripts/backup_and_restore.sh` script to create a full backup on the source machine, then install Mailcow on the target machine as usual, copy over your `mailcow.conf` and use the same script to restore your backup to the target machine.
+##### Alternatively, you can use the `./helper-scripts/backup_and_restore.sh` script to create a full backup on the source machine, then install mailcow on the target machine as usual, copy over your `mailcow.conf` and use the same script to restore your backup to the target machine.
 
 **1\.** 
 Install [Docker](https://docs.docker.com/engine/installation/linux/) and [Docker Compose](https://docs.docker.com/compose/install/) on your new server.