changes for cse.service (Wants,After, and WantedBy)

[bsmr]

There are two corrections included for the cse.service file:

• Wants and After require the dependencies delimited by spaces, not commas (systemd.syntax — General syntax of systemd configuration files)
• default.target looks problematic: user service don't start up automatically but manually
  That's why I replaced it with multi-user.target

I also changed the default.target to multi-user.target, because systemctrl get-default reports this on a VMware Photon OS 2.0 system, but I'm not sure, if default.target raises any faults.

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This change is 

[sahithi]

Have you tested this both on Ubuntu and Photon? We will test this soon and submit your PR if found no issues.