LinkTarget.mk: only call gb_Object__command_dep if dep file doesn't exist
LinkTarget.mk: only call gb_Object__command_dep if dep file doesn't exist

(infinite loop regression from a4e2453b42b54ba904c1ee8ad07e26f1e6d939e5)

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core