Fix substituter.sh line breaks

After building the image from Packaging Alfresco Share module, when we're trying to actually run it (docker run NEW_IMAGE_TAG) we're getting the following error:

standard_init_linux.go:211: exec user process caused "no such file or directory"

The source of the problem are the line breaks from substituter.sh script, which are in DOS/Windows format (CRLF). Converting the into Unix format (LF) will fix the issue.