Fix systemctl enable neo4j.service documentation (#903)

The documentation for neo4j.service systemctl was invalid. 
The command "systemctl daemon-reload" must not be part of the
neo4j.service definition.

Author: Tavark

modules/ROOT/pages/installation/linux/tarball.adoc

@@ -87,16 +87,15 @@ TimeoutSec=120
 
 [Install]
 WantedBy=multi-user.target
-//Reload systemctl to pick up the new service file
-systemctl daemon-reload
 ----
 
-. Configure Neo4j to start at boot time:
+. Reload systemctl to pick up the new service file and configure Neo4j to start at boot time:
 +
 [source, shell]
 ----
 systemctl enable neo4j
 ----
+
 . Start Neo4j:
 +
 [source, shell]
@@ -197,4 +196,4 @@ neo4j	hard	nofile	60000
 sudo systemctl daemon-reload
 ----
 
-. Reboot your machine.
+. Reboot your machine.