Fix accidental reintroduction of jemalloc

Author: johnthagen

src/main.rs

@@ -1,9 +1,9 @@
 // Use the system allocator instead of bundling
 // jemalloc into the binary.
-//use std::alloc::System;
-//
-//#[global_allocator]
-//static A: System = System;k
+use std::alloc::System;
+
+#[global_allocator]
+static A: System = System;
 
 fn main() {
     println!("Hello, world!");