message: replace with more robust git command in cmake message
diff: @@ -33,9 +33,8 @@ else()
  if (NOT EXISTS ${BLT_SOURCE_DIR}/SetupBLT.cmake)
  message(FATAL_ERROR
  "Cannot locate BLT. "
  - "Either run the following two commands in your git repository: \n"
  - " git submodule init\n"
  - " git submodule update\n"
  + "Either run the following command in your git repository: \n"
  + " git submodule update --init --recursive\n"
  "Or add -DBLT_SOURCE_DIR=/path/to/blt to your CMake command." )
  endif()
  endif()
  