Remove llvm.ccache option from config.example.toml

Author: Kobzol

config.example.toml

@@ -87,10 +87,6 @@
 # Whether to build LLVM with support for it's gpu offload runtime.
 #offload = false
 
-# Indicates whether ccache is used when building LLVM. Set to `true` to use the first `ccache` in
-# PATH, or set an absolute path to use a specific version.
-#ccache = false
-
 # When true, link libstdc++ statically into the rustc_llvm.
 # This is useful if you don't want to use the dynamic version of that
 # library provided by LLVM.