fix bug:cocos run -p linux

 ... ... 
 File "~/Cocos/cocos2d-x-3.0rc0/tools/cocos2d-console/bin/../plugins/project_compile/project_compile.py", line 36, in copy_files_in_dir
    os.makedirs(new_dst)
  File "/usr/lib/python2.7/os.py", line 157, in makedirs
    mkdir(name, mode)
OSError: [Errno 17] File exists: