Update Spigot build script to latest BuildTools changes.

It is required now to explicitly specify whether to also build
CraftBukkit.

installSpigot.sh

@@ -16,7 +16,7 @@ git config --global --unset core.autocrlf
 
 # Build spigot
 echo "Building Spigot using Spigot Build Tools for minecraft version $1 (this might take a while)"
-java -Xmx1500M -jar BuildTools.jar --rev $1 | grep Installing
+java -Xmx1500M -jar BuildTools.jar --rev $1 --compile CRAFTBUKKIT,SPIGOT | grep Installing
 
 # Reset autocrlf
 git config --global core.autocrlf $git_autocrlf