fix(groups): allow to remove group with backslashes from user
fix(groups): allow to remove group with backslashes from user

related to #CAM-2391

tcrossland/camunda-bpm-webapp,tcrossland/camunda-bpm-webapp,TitanUser/camunda-bpm-webapp,xlinur/camunda-bpm-webapp,tcrossland/camunda-bpm-webapp,TitanUser/camunda-bpm-webapp,xlinur/camunda-bpm-webapp,xlinur/camunda-bpm-webapp,TitanUser/camunda-bpm-webapp