Merge pull request #107 from pespantelis/patch-1

Remove duplicate word

Author: yyx990803

source/guide/components.md

@@ -260,7 +260,7 @@ The `type` can be one of the following native constructors:
 - Object
 - Array
 
-In addition, `type` can also be a custom constructor function and the the assertion will be made with an `instanceof` check.
+In addition, `type` can also be a custom constructor function and the assertion will be made with an `instanceof` check.
 
 When a prop validation fails, Vue will refuse the set the value on the child component, and throw a warning if using the development build.