debian/maintscripts-functions: Remove empty /usr/share/man/ directories.

debian/changelog

@@ -3,6 +3,7 @@ postgresql-common (257) UNRELEASED; urgency=medium
   * Move systemd unit files to /usr on releases that support it.
   * debian/maintscripts-functions: More carefully build update-alternatives
     command line. Hopefully fixes "link and path can't be the same" errors.
+  * debian/maintscripts-functions: Remove empty /usr/share/man/ directories.
   * pg_backupcluster: Add hostname, machine-id, and machine-deployment (from
     /etc/machine-info) to backup status; use machine-readable timestamps for
     starttime/endtime; sort keys.

debian/maintscripts-functions

@@ -49,6 +49,7 @@ _unlink_manpages() {
     mkdir -p /usr/share/man/man1 /usr/share/man/man3 /usr/share/man/man7
     section=$(echo "$NAME" | sed -e 's/.*\.\(.*\)\..*/man\1/')
     update-alternatives --remove $NAME /usr/share/postgresql/$VERSION/man/$section/$NAME
+    rmdir --ignore-fail-on-non-empty -p /usr/share/man/man1 /usr/share/man/man3 /usr/share/man/man7
 }
 
 _remove_tsearch() {