Remove duplicate word

Author: zousandian

src/guide/components.md

@@ -258,7 +258,7 @@ Compare the syntax:
 <child :msg.once="parentMsg"></child>
 ```
 
-The two-way binding will sync the change of child's `msg` property back to the parent's `parentMsg` property. The one-time binding, once set up, will not sync future changes between the the parent and the child.
+The two-way binding will sync the change of child's `msg` property back to the parent's `parentMsg` property. The one-time binding, once set up, will not sync future changes between the parent and the child.
 
 <p class="tip">Note that if the prop being passed down is an Object or an Array, it is passed by reference. Mutating the Object or Array itself inside the child **will** affect parent state, regardless of the binding type you are using.</p>