fix rustfmt issue in src/callbacks.rs

Author: jrandall

src/callbacks.rs

@@ -25,7 +25,9 @@ impl Default for MacroParsingBehavior {
 
 /// A trait to allow configuring different kinds of types in different
 /// situations.
-pub trait ParseCallbacks: fmt::Debug + UnwindSafe + dyn_clone::DynClone {
+pub trait ParseCallbacks:
+          fmt::Debug + UnwindSafe + dyn_clone::DynClone
+{
     /// This function will be run on every macro that is identified.
     fn will_parse_macro(&self, _name: &str) -> MacroParsingBehavior {
         MacroParsingBehavior::Default