LU-13481 test: run sanity 33h with more files

LU-13481 test: run sanity 33h with more files

Run sanity 33h with more files to avoid failure with small samples.

Test-parameters: trivial testlist=sanity env=ONLY=33h,ONLY_REPEAT=500

Signed-off-by: Lai Siyao <lai.siyao@whamcloud.com>
Change-Id: If14a852289ffc5907637a9dac6ed48890ced5586
Reviewed-on: https://review.whamcloud.com/39219
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: James Nunez <jnunez@whamcloud.com>