package ldap-account-manager 4.0.1-1 failed to install/upgrade: subprocess installed post-removal script returned error exit status 2

[Frank Bonnet]

unable to remove this package , it blocks nginx package installation , and I NEED nginx !
thanks a lot

ProblemType: Package
DistroRelease: Ubuntu 13.04
Package: ldap-account-manager 4.0.1-1
ProcVersionSignature: Ubuntu 3.8.0-23.34-generic 3.8.11
Uname: Linux 3.8.0-23-generic i686
NonfreeKernelModules: nvidia
ApportVersion: 2.9.2-0ubuntu8.1
Architecture: i386
Date: Mon Jun 3 16:34:25 2013
DpkgTerminalLog:
 Removing ldap-account-manager ...
 /etc/init.d/apache2: 51: .: Can't open /etc/apache2/envvars
 invoke-rc.d: initscript apache2, action "reload" failed.
 dpkg: error processing ldap-account-manager (--remove):
  subprocess installed post-removal script returned error exit status 2
DuplicateSignature: package:ldap-account-manager:4.0.1-1:subprocess installed post-removal script returned error exit status 2
ErrorMessage: subprocess installed post-removal script returned error exit status 2
InstallationDate: Installed on 2011-06-03 (734 days ago)
InstallationMedia: Ubuntu 10.04.2 LTS "Lucid Lynx" - Release i386 (20110211.1)
MarkForUpload: True
PackageArchitecture: all
SourcePackage: ldap-account-manager
Title: package ldap-account-manager 4.0.1-1 failed to install/upgrade: subprocess installed post-removal script returned error exit status 2
UpgradeStatus: Upgraded to raring on 2013-05-14 (23 days ago)

[Roland Gruber (post-rolandgruber)]

/etc/init.d/apache2: 51: .: Can't open /etc/apache2/envvars
 invoke-rc.d: initscript apache2, action "reload" failed.

Seems to be a bug in Apache, please contact its maintainers.