Cannot add groups

i have managed to install playsms 1.4 on php7 virtualbox.

everything seems to be working but im unable to add a group under phonebook. i filled all three fields but get error. saying unable to add group

thanks
sabeel

fixed https://github.com/antonraharja/playSMS/commit/54bf6e2e3ba606ba899e44c481dbd908666c516d