zkt: update to 1.1.6.

zkt 1.1.6 -- 04. Jan 2023

* misc New configure.ac file generated by 'autoscan'

* bug Jan M端nnich found out that "-fcommon" is needed to compile ZKT
with gcc 10.
This is because of a double external definition caused by
including header files while defining "extern" as empty.
This is fixed now by eliminating includes within include files
so "-fcommon" is not needed.

* misc Increase of some string vars because of compiler warnings

* bug Fixed an empty statement (semicolon) in freeconfig()
(Thank you gcc!)

zkt 1.1.5 -- 17. Jun 2019

* misc Option -r of dnssec-keygen has been deprecated since 9.13 (or so)
Usage removed in dki_new()

* func recursive_file_mtime() function added by Sven Stickroth
This is useful if several zone files are included in a main zone.db
file to track a change of any of the input files.
It is not compiled in by default (use configure --enable-inc-file-tracking
to enable) because for large zone files this could be a time consuming process.
It is possible to add all included files to the local config parameter
"DependFiles" instead. (Use zkt-conf <zonefile> to get a list of files to be added).

* misc Log name of zone if KSK is expired
Thanks to Sven Stickroth

* misc DEST_DIR added to Makefile to install executables at common places
Thanks to Sven Stickroth

* bug Fix typos in rollover.c
make clean also cleans OBJ_KLS files
Thanks to Sven Stickroth

(fcambus)