Use correct github url to find commands.json
Use correct github url to find commands.json

Once this is merged:
  - merge the latest changes to commands.json in antirez/redis-doc
  - re-run: utils/generate-command-help.rb > src/help.h

Then we'll have nice and easy tab-completed help in redis-cli again.

Closes #1909

HunanTV/redis,darksideofthemoo/redis-histogram,ttuna/msot-redis,spearhead-ea/redis,darksideofthemoo/redis-histogram,slfs007/mk-redis,splitice/redis,ramonsnir/redis,spearhead-ea/redis,slfs007/mk-redis,darksideofthemoo/redis-histogram,himoca/redis,louisliangjun/redis,HunanTV/redis,ramonsnir/redis,jxwr/redis,maodeyi/redis_lua,splitice/redis,MSOpenTech/redis,spearhead-ea/redis,MSOpenTech/redis,xuzhezhaozhao/redis_reading,xuzhezhaozhao/redis_reading,ksarch-saas/redis,ramonsnir/redis,slfs007/mk-redis,himoca/redis,ksarch-saas/redis,maodeyi/redis_lua,ksarch-saas/redis,MSOpenTech/redis,ttuna/msot-redis,darksideofthemoo/redis-histogram,louisliangjun/redis,jxwr/redis,splitice/redis,ksarch-saas/redis,maodeyi/redis_lua,xuzhezhaozhao/redis_reading,himoca/redis,splitice/redis,ttuna/msot-redis,MSOpenTech/redis,HunanTV/redis,HunanTV/redis,MSOpenTech/redis,louisliangjun/redis,jxwr/redis,louisliangjun/redis,xuzhezhaozhao/redis_reading,ttuna/msot-redis,ttuna/msot-redis