Fix lintian's possible-unindented-list-in-extended-description

* The description section from control file in .deb was reformatted according
  to documentation (Debian Policy Manual, Section 5.6.13. Description):
  https://www.debian.org/doc/debian-policy/ch-controlfields.html#description

packaging/debian/control

@@ -17,12 +17,12 @@ Description: Mentat - SIEM for network operators
  .
  For more information please visit our web page:
  .
- * https://mentat.cesnet.cz/
+  * https://mentat.cesnet.cz/
  .
  Documentation is available online:
  .
- * https://alchemist.cesnet.cz/mentat/doc/production/html/manual.html
+  * https://alchemist.cesnet.cz/mentat/doc/production/html/manual.html
  .
  To report a bug please use our issue tracking system:
  .
- * https://homeproj.cesnet.cz/projects/mentat
+  * https://homeproj.cesnet.cz/projects/mentat