making portable sed statements is not worth the hassle

change to git's own formatting capabilities by using the text-wrap
option with only indent settings/no rewrapping → %w(0,8,8)
and also omit the additional empty line when there only is a summary,
but no body in the commit message (remove a %n, make it %+b)
finally drop the now no-longer needed starmarker (the @)

previous differences in sed caused unnecessarily large diffs for
distro-packagers, see
https://anonscm.debian.org/git/pkg-openoffice/libreoffice-dictionaries.git/commit/?h=upstream&id=3dceac52f75030e87519e73b42babde51e471d9f
now it will change once, but then we can put all the blame on git :-)

Change-Id: Ifa719d062582c54c9c23b4ae08d4bae9a396e83c

bin/lo-pack-sources

@@ -126,8 +126,8 @@ sub generate_lo_module_changelog($$$)
     $log_name .= "-$module_dirname{$module}" if ($module_dirname{$module});
     print "Generating changelog for $module...\n";
     system ("cd $source_dir/$module_dirname{$module} && " .
-            "git log --date=short --pretty='format:@%cd  %an  <%ae>  [%H]%n%n%s%n%n%e%b' | " .
-            "  sed -e 's/^/\t/' -e 's/^\t@//' >$lo_module_release_topdir/$log_name" ) &&
+            "git log --date=short --pretty='format:%cd  %an  <%ae>  [%H]%n%n%w(0,8,8)%s%n%e%+b' | " .
+            ">$lo_module_release_topdir/$log_name" ) &&
         die "Error: generating failed: $!\n";
 }