Github DownloadProblem

Hello,
I have downloaded the Github repository in https://github.com/DroidPlanner/Tower using the method shown in the download method shown in https://github.com/DroidPlanner/Tower/wiki/Build-Setup---GIT and tried running it on my Android Studio but kept getting the following error.

Is there a simple way to fix this problem ?

That’s only a warning, it won’t stop the build from working