logrotate: check if file exited before create a soft link

component/logrotate/buildout.cfg

@@ -11,7 +11,7 @@ url = https://github.com/logrotate/logrotate/releases/download/3.11.0/logrotate-
 md5sum = 3a9280e4caeb837427a2d54518fbcdac
 # BBB this is only for backward-compatibility.
 post-install =
-  ln -s . ${buildout:parts-directory}/${:_buildout_section_name_}/usr
+  test -h ${buildout:parts-directory}/${:_buildout_section_name_}/usr || rm -rf ${buildout:parts-directory}/${:_buildout_section_name_}/usr && ln -s . ${buildout:parts-directory}/${:_buildout_section_name_}/usr
 environment =
   PATH=${xz-utils:location}/bin:%(PATH)s
   CPPFLAGS=-I${popt:location}/include