message: Remove empty ENGINE_PARAMS arguments
diff: @@ -48,26 +48,26 @@ set (DiscardWriter_CMD "run_multi_test -test_protocol one_to_one -verbose -nw 1
  function(remove_engine_params_placeholder dst_str src_str )
  - message (STATUS "before replace, src_string is ${src_str}")
  string(REGEX REPLACE "([^ ]*),ENGINE_PARAMS" "\\1" src_str "${src_str}")
  - message (STATUS "after replace, src_string is ${src_str}")
  + if ("{src_string}" MATCHES "ENGINE_PARAMS")
  + # empty engine params remains
  + string(REGEX REPLACE "-warg *--engine_params *-warg *ENGINE_PARAMS" "" src_str "${src_str}")
  + string(REGEX REPLACE "-arg *ENGINE_PARAMS" "" src_str "${src_str}")
  + endif()
  +
  set(${dst_str} ${src_str} PARENT_SCOPE)
  endfunction()
  function(add_engine_param dst_string src_string engine_param)
  set (tmp_string "")
  - message(STATUS "before add engine Src string is ${src_string}")
  if("${src_string}" MATCHES ",ENGINE_PARAMS")
  string(REGEX REPLACE ",ENGINE_PARAMS" ",${engine_param},ENGINE_PARAMS" tmp_string ${src_string})
  - message(status "ding first")
  elseif("${src_string}" MATCHES "ENGINE_PARAMS")
  string(REGEX REPLACE "ENGINE_PARAMS" "${engine_param},ENGINE_PARAMS" tmp_string ${src_string})
  - message(status "ding second")
  else ()
  message(WARNING "ENGINE_PARAMS not found in string ${src_string}")
  endif ()
  - message(STATUS "after add engine Src string is ${src_string}")
  set(${dst_string} "${tmp_string}" PARENT_SCOPE)
  endfunction()
  @@ -79,11 +79,8 @@ function(MutateTestSet out_list name param in_list )
  message(SEND_ERROR "Staging-Common MutateTestSet ${basename} has no defined ${basename}_CMD")
  endif()
  add_engine_param(tmp_cmd "${${basename}_CMD}" ${param})
  - message(STATUS "New command is ${tmp_cmd}\n")
  set(${modname}_CMD ${tmp_cmd} PARENT_SCOPE)
  - message( STATUS "Establishing command ${modname}_CMD")
  if (NOT "${${basename}_TIMEOUT}" STREQUAL "")
  - message (STATUS "ACTUAL TIMEOUT SET for ${basename}_TIMEOUT, ${${basename}_TIMEOUT}")
  set(${modname}_TIMEOUT ${${basename}_TIMEOUT} PARENT_SCOPE)
  endif()
  if (NOT "${${basename}_PROPERTIES}" STREQUAL "")
  