GitHub push error

[alexbran8]

! [rejected] ec1354b33bdfa6a2571ce271d589dd9080d14a94 -> gh-pages (fetch first)
error: failed to push some refs to 'https://github.com/alexbran8/webservices.git'
hint: Updates were rejected because the remote contains work that you do
hint: not have locally. This is usually caused by another repository pushing
hint: to the same ref. You may want to first integrate the remote changes
hint: (e.g., 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.

Did you encounter this error as well? First deploy works fine, than it works only if I delete de branch which is not a sustainable solution...