correct lemmas limit in the multi-check mode #299

Job	Run time
ubuntu-latest\|debug\|--enable-mcsat\|CC=gcc CXX=g++	7m 27s
ubuntu-latest\|debug\|--enable-mcsat\|CC=clang CXX=clang++	8m 1s
ubuntu-latest\|debug\|--enable-thread-safety\|CC=gcc CXX=g++	3m 24s
ubuntu-latest\|debug\|--enable-thread-safety\|CC=clang CXX=clang++	3m 48s
ubuntu-latest\|release\|--enable-mcsat\|CC=gcc CXX=g++	4m 26s
ubuntu-latest\|release\|--enable-mcsat\|CC=clang CXX=clang++	4m 44s
ubuntu-latest\|release\|--enable-thread-safety\|CC=gcc CXX=g++	2m 11s
ubuntu-latest\|release\|--enable-thread-safety\|CC=clang CXX=clang++	2m 8s
ubuntu-latest\|gcov\|--enable-mcsat\|CC=gcc CXX=g++	7m 14s
ubuntu-latest\|debug\|--enable-thread-safety --enable-mcsat\|CC=gcc CXX=g++	7m 11s
	50m 34s

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