PrAlgorithms - Fix MVA leak
Address sanitizer error
Direct leak of 824 byte(s) in 1 object(s) allocated from:
#0 0x7fcad5ca9116 in operator new(unsigned long) ../../../../gcc-7.3.0/libsanitizer/lsan/lsan_interceptors.cc:162
#1 0x7fcab07a8bd3 in PrMatchNN::initialize() /workspace/build/REC/REC_HEAD/Pr/PrAlgorithms/src/PrMatchNN.cpp:48
#2 0x7fcabdd5a2be in Algorithm::sysInitialize() /workspace/build/GAUDI/GAUDI_HEAD/GaudiKernel/src/Lib/Algorithm.cpp:120