Contracts three paragraphs, one style improvement.

As per @ben's suggestion, the three paragraphs dealing with adapting the systemd config to the system at hand have been compounded into one.
I also got rid of a double "make sure" for style.

Author: reitzig

book/04-git-server/sections/git-daemon.asc

@@ -47,10 +47,8 @@ WantedBy=multi-user.target
 ----
 
 You might have noticed that Git daemon is started here with `git` as both group and user.
-
-Modify it to fit your needs and make sure provided user exists on the system.
-
-Also, make sure that the Git binary is indeed located at `/usr/bin/git` and change the path if necessary.
+Modify it to fit your needs and make sure the provided user exists on the system.
+Also, check that the Git binary is indeed located at `/usr/bin/git` and change the path if necessary.
 
 Finally, you'll run `systemctl enable git-daemon` to automatically start the service on boot, and can start and stop the service with, respectively, `systemctl start git-daemon` and `systemctl stop git-daemon`.