debian/generate-config: Re-compile the dconf database unconditionally.

Previously we tried to determine whether running dconf compile was really necessary by comparing the timestamps of the input and output files in a make-like fashion. This is complicated and can lead to unexpected behavior: For example, the logic would only consider keyfiles named *-settings in its decision, but dconf would parse all files, regardless of the name.

Since both the CPU and IO load are negligible (see the output below) and this will normally only run once per boot-up, we can just remove the timestamp logic and unconditionally run the compilation.

$ time dconf compile dummy /usr/share/gdm/dconf

real	0m0.007s
user	0m0.000s
sys	0m0.007s
$ ls -l dummy
-rw-r--r-- 1 alexander alexander 4580 Jul 27 17:47 dummy
$