updated comment on api_perf model
updated comment on api_perf model

slashk/goldstone-server,slashk/goldstone-server,slashk/goldstone-server,Solinea/goldstone-server,slashk/goldstone-server,Solinea/goldstone-server,Solinea/goldstone-server,Solinea/goldstone-server,slashk/goldstone-server,Solinea/goldstone-server