What will you do when your phone ringing during your sholat jama'ah?

You should move your hand to turn of your mobile phone and make sure it won't rang again disturbing the prayer. Because syaikh al utsaimin ever give fatwa that movement during shalat to turning of mobile phone because its ringing id disturbing sholat and the muslimin who praying can't get khusyu' because the sound is permitted and doesn't make sholat cancelled or failed.

Surah Al-Baqara, Verse 45:
وَاسْتَعِينُوا بِالصَّبْرِ وَالصَّلَاةِ وَإِنَّهَا لَكَبِيرَةٌ إِلَّا عَلَى الْخَاشِعِينَ
Nay, seek (Allah's) help with patient perseverance and prayer: It is indeed hard, except to those who bring a lowly spirit [khusyu']