corrected the representation of the combination of keys "alt + →"

replaced the '-' delimiter by a '+'
replaced the xml entity that represents the right arrow by the symbol of the right arrow ('→')

Author: aollier

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

@@ -13,7 +13,7 @@ Fortunately, this process is very well-documented and supported.
 
 There are a few methods you can pursue to install GitLab.
 To get something up and running quickly, you can download a virtual machine image or a one-click installer from https://bitnami.com/stack/gitlab[], and tweak the configuration to match your particular environment.(((bitnami)))
-One nice touch Bitnami has included is the login screen (accessed by typing alt-→); it tells you the IP address and default username and password for the installed GitLab.
+One nice touch Bitnami has included is the login screen (accessed by typing alt+→); it tells you the IP address and default username and password for the installed GitLab.
 
 [[bitnami]]
 .The Bitnami GitLab virtual machine login screen.