config/ltsugar.m4, config/ltversion.m4,
  config/lt~obsolete.m4: Upgrade lintool to 2.4.6


git-svn-id: https://svn.code.sf.net/p/amanda/code/amanda/branches/3_3@6530 a8d146d6-cc15-0410-8900-af154a0219e0