Avoid typing FTP password

I have a lightweight checkout of a branch located on an FTP server:
   bzr checkout --lightweight ftp://username:password@server/remotepath/ c:/localpath

If I want to update my checkout, it asks for a password
   cd c:/localpath
   bzr update
   FTP username@server password:
   Tree is up to date at revision 5 of branch ftp://username:password@server/remotepath/

Since I want to call "bzr update" from within PHP, I don't want to be prompted for a password. My current workaround is adding the password plaintext to c:/localpath/.bzr/branch/location
   ftp://username:password@server/remotepath/

Is there a better (more secure) way of doing this?