fix json listing eror in smc_compute using the same strategy as in git_ls.py
fix json listing eror in smc_compute using the same strategy as in git_ls.py

tscholl2/smc,sagemathinc/smc,DrXyzzy/smc,DrXyzzy/smc,sagemathinc/smc,tscholl2/smc,sagemathinc/smc,sagemathinc/smc,tscholl2/smc,DrXyzzy/smc,tscholl2/smc,tscholl2/smc,DrXyzzy/smc