new behavior in paddle_build.sh is failing nightly build

[putcn]

paddle_build.sh build is no longer generating dockerfile in build directory, which is failing docker build of paddle nightly.
http://172.19.32.197:8111/viewLog.html?tab=buildLog&logTab=tree&filter=debug&expand=all&buildId=35138&_focus=6672

[putcn]

fixed by: #10719