TT#154255 Remove redis dependency from unit file

We are migrating from redis to keydb so for now we need to support both
so we should not depend on specific key-value storage in unit file but
should use database.key_value.flavor value in override file.

But we can't redefine dependencies in override file just add additional
ones. So remove it from unit file.

Change-Id: I16e94e938bd9f1da14e1068bc6b94485b08a4ca5

debian/ngcp-mediator.service

@@ -1,10 +1,8 @@
 [Unit]
 Description=NGCP Mediator
 After=mariadb.service
-After=redis-server.service
 After=remote-fs.target
 Wants=mariadb.service
-Wants=redis-server.service
 
 [Service]
 Type=notify