Correct a typo.

Thanks to [agneevX](https://github.com/agneevX).

diff --git a/INSTALL.md b/INSTALL.md
index 2d21b9c5fb7c90b8ec74e5174c644b8d90aee89d..714eb0fd233c1198de92d319246ffee866fadc0c 100644 (file)
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -34,7 +34,7 @@ Remove it as follows:
 Do this until no more copies of `shairport-sync` are found.
 
 ### Remove Old Startup Scripts
-You should also remove the startup script files `/etc/systemd/system/shairport-sync.service` and `/etc/init.d/shairport-sync` if they exist – new ones will be installed in necessary.
+You should also remove the startup script files `/etc/systemd/system/shairport-sync.service` and `/etc/init.d/shairport-sync` if they exist – new ones will be installed if necessary.
 
 ### Reboot after Cleaning Up
 If you removed any installations of Shairport Sync or any of its startup script files in the last two steps, you should reboot.