Android Studio 0.4 Duplicate files copied in APK META-INF/LICENSE.txt

After I have updated my Studio from 0.3.7 to 0.4.0, I can't compile my project. I found a solution on stackoverflow: Duplicate files copied (Android Studio 0.4.0)

I updated my project to gradle 0.7.+, but I don't know where I must put the next strings:

android {

    packagingOptions {
       exclude 'META-INF/LICENSE.txt'
    }
}

My logcat: log

Execution failed for task ':Prog:packageDebug'.
> Duplicate files copied in APK META-INF/LICENSE.txt
    File 1: /home/scijoker/AndroidStudioProjects/ProgProject/Prog/libs/httpclient-4.1.1.jar
    File 2: /home/scijoker/AndroidStudioProjects/ProgProject/Prog/libs/httpclient-4.1.1.jar

P.S. Develop in ubuntu 13.04