Ignore non-string non-list values

Might be present in legacy configuration files, they serve
no purpose in zonetool.
4 jobs for master in 1 minute and 25 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #8821
run_tests

00:00:29

 
  Build Src
passed #8822
build:src

00:00:14

 
  Build Pkg
passed #8823
build:pkg

00:00:22

 
  Upload
passed #8824
upload:pkg

00:00:19