Fix path in rust recipe

The recipe was moved in !310 (merged) and this relative path needs to be changed

recipes/development/rust/config.toml

@@ -24,5 +24,5 @@ cxx = "x86_64-unknown-redox-g++"
 ar = "x86_64-unknown-redox-ar"
 linker = "x86_64-unknown-redox-gcc"
 # Nasty path, please fix
-llvm-config = "../../../bin/x86_64-unknown-redox-llvm-config"
+llvm-config = "../../../../bin/x86_64-unknown-redox-llvm-config"
 crt-static = false