Remove reference to diabetes

1. this isn't actually true about diabetes
2. people with diabetes will get *real sad* when reading this
3. it isn't actually necessary.

lifetimes.md

@@ -52,8 +52,7 @@ likely desugar to the following:
 }
 ```
 
-Wow. That's... awful. Let's all take a moment to thank Rust for being a
-diabetes-inducing torrent of syrupy-goodness.
+Wow. That's... awful. Let's all take a moment to thank Rust for making this easier.
 
 Actually passing references to outer scopes will cause Rust to infer
 a larger lifetime: