Mcsat ufnra model fix #464

Job	Run time
ubuntu-latest\|debug\|--enable-mcsat\|CC=gcc CXX=g++	7m 58s
ubuntu-latest\|debug\|--enable-mcsat\|CC=clang CXX=clang++	8m 47s
ubuntu-latest\|debug\|--enable-thread-safety\|CC=gcc CXX=g++	3m 55s
ubuntu-latest\|debug\|--enable-thread-safety\|CC=clang CXX=clang++	4m 21s
ubuntu-latest\|release\|--enable-mcsat\|CC=gcc CXX=g++	5m 3s
ubuntu-latest\|release\|--enable-mcsat\|CC=clang CXX=clang++	5m 23s
ubuntu-latest\|release\|--enable-thread-safety\|CC=gcc CXX=g++	2m 42s
ubuntu-latest\|release\|--enable-thread-safety\|CC=clang CXX=clang++	2m 51s
ubuntu-latest\|gcov\|--enable-mcsat\|CC=gcc CXX=g++	9m 4s
ubuntu-latest\|debug\|--enable-thread-safety --enable-mcsat\|CC=gcc CXX=g++	9m 6s
	59m 10s

Provide feedback