Fix SCons version check.
Fix SCons version check.

SConstruct:
    Handle SCons version check error when running
    on SCons 0.96 and previous.

andrewfu0325/gem5-aladdin,haowu4682/gem5,andrewfu0325/gem5-aladdin,haowu4682/gem5,andrewfu0325/gem5-aladdin,LingxiaoJIA/gem5,LingxiaoJIA/gem5,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,haowu4682/gem5,LingxiaoJIA/gem5,haowu4682/gem5,LingxiaoJIA/gem5,haowu4682/gem5,LingxiaoJIA/gem5,LingxiaoJIA/gem5,andrewfu0325/gem5-aladdin,haowu4682/gem5,andrewfu0325/gem5-aladdin,haowu4682/gem5,LingxiaoJIA/gem5,haowu4682/gem5,haowu4682/gem5