Remove redundant time-limit specifications in benchmark definitions.
The scripts now automatically pass the -timelimit parameter to CPAchecker
with the correct time limit specified in the benchmark file,
if there is a soft time limit.

git-svn-id: https://svn.sosy-lab.org/software/cpachecker/trunk@13092 4712c6d2-40bb-43ae-aa4b-fec3f1bdfe4c