Update beampixel_dqm_sourceclient-live_cfg.py

I've updated the configuration file for the beam spot monitor based on pixel information only.
The main modification concerns the new input variable "pixelHitCollection".
Other modifications are related to the removal of unused sequences and better indentation of the code.
Merge pull request #1 from dinardo/master

Update beampixel_dqm_sourceclient-live_cfg.py