fix: set lactd to run without requiring graphical mode (#221)

The lact daemon is usable in a command-line environment, since it
can be interfaced with via the command line. As it's useful in
headless setups, alter the systemd service unit to permit it.

res/lactd.service

@@ -6,4 +6,4 @@ After=multi-user.target
 ExecStart=lact daemon
 
 [Install]
-WantedBy=graphical.target
+WantedBy=multi-user.target