corrects ProbModelXMLWriter class
corrects ProbModelXMLWriter class

ankurankan/pgmpy,kislayabhi/pgmpy,pratyakshs/pgmpy,kislayabhi/pgmpy,liquidmetal/pgmpy,khalibartan/pgmpy,jhonatanoliveira/pgmpy,sandeepkrjha/pgmpy,anaviltripathi/pgmpy,kris-singh/pgmpy,palashahuja/pgmpy,vivek425ster/pgmpy,ankurankan/pgmpy,anaviltripathi/pgmpy,yashu-seth/pgmpy,pgmpy/pgmpy,pgmpy/pgmpy,liquidmetal/pgmpy,jhonatanoliveira/pgmpy,pratyakshs/pgmpy,abinashpanda/pgmpy,vivek425ster/pgmpy,yashu-seth/pgmpy,abinashpanda/pgmpy,khalibartan/pgmpy,kris-singh/pgmpy,sandeepkrjha/pgmpy,palashahuja/pgmpy