Update Package from git Source

[Isaac <puchrojo@gmail.com>]

Hello,
I try to update ddclient to the last version. However, I think I donâ??t really understand 
the combination between the sources from git and the tarball / quilt. 
So I write a script with the minimal process to create and update a hello-world package. 
https://github.com/puchrojo/badpeswg
I think the problem is on bin/07-update-package 
https://raw.githubusercontent.com/puchrojo/badpeswg/master/bin/07-update-package 

That is the Error I get:
gbp buildpackage
gbp:info: Performing the build
 dpkg-buildpackage -us -uc -ui -i -I
[...]
dpkg-source: error: aborting due to unexpected upstream changes, see /tmp/dummy-hello_0.0.1-2.diff.ONoIGT             
dpkg-buildpackage: error: dpkg-source -i -I -b . subprocess returned exit status 2 
dpkg-buildpackage -us -uc -ui -i -I failed 
gbp:error: 'debuild -i -I' failed: it exited with 29

If I try to commit with â??dpkg-source â??commitâ?? I get the dummy-hello_0.0.1-2_amd64.deb and not the 0.1.2 that I want from the git changes. 
What I try to get
1. The main source are git and not the tarball. 
2. Tarbal / Quilt sould be build to compatibility with Debian Policy and other apps.
What are Iâ??m missing?
Regards,
Isaac Puch